| **BORROWINGS (Tables)**                          | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          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| SHUSA                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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| **Debt Instrument [Line Items]**                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  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| Schedule of Borrowings and Other Debt Obligation | The following table presents information regarding the Parent Company borrowings and other debt obligations at the dates indicated: June 30, 2016 December 31, 2015 Balance EffectiveRate Balance EffectiveRate (dollars in thousands)4.625% senior notes, due April 2016 $— —% $475,723 4.85%Senior notes, due November 2017(1)598,263 2.33% — —%3.45% senior notes, due August 2018498,198 3.62% 497,800 3.62%2.70% senior notes, due May 2019996,226 2.84% — —%2.65% senior notes, due April 2020993,907 2.82% 993,151 2.82%4.50% senior notes, due July 20251,094,717 4.56% 1,094,483 4.56%Junior subordinated debentures - Capital Trust VI, due June 203669,786 7.91% 69,775 7.91%Common securities - Capital Trust VI10,000 7.91% 10,000 7.91%Junior subordinated debentures - Capital Trust IX, due July 2036149,419 2.44% 149,404 2.18%Common securities - Capital Trust IX4,640 2.44% 4,640 2.18%     Total Parent Company borrowings and other debt obligations$4,415,156 3.36% $3,294,976 3.91%(1)  These notes bear interest at a rate equal to three-month LIBOR plus 145 basis points per annum.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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| Santander Bank                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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| **Debt Instrument [Line Items]**                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  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| Schedule of Borrowings and Other Debt Obligation | The following table presents information regarding the Bank's borrowings and other debt obligations at the dates indicated:  June 30, 2016 December 31, 2015 Balance EffectiveRate Balance EffectiveRate (dollars in thousands)2.00% senior notes, due January 2018$747,257 2.24% $746,381 2.24%Senior notes, due January 2018(1)249,557 1.68% 249,415 1.31%8.750% subordinated debentures, due May 2018498,520 8.92% 498,175 8.92%Subordinated term loan, due February 2019125,188 6.53% 130,899 6.15%FHLB advances, maturing through July 20199,000,000 1.05% 13,885,000 1.40%REIT preferred, due May 2020155,692 13.45% 154,930 13.66%Subordinated term loan, due August 202229,648 8.28% 30,344 7.89%     Total Bank borrowings and other debt obligations$10,805,862 1.77% $15,695,144 1.85%(1)  These notes will bear interest at a rate equal to three-month LIBOR plus 93 basis points per annum.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               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| SC                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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| **Debt Instrument [Line Items]**                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  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| Schedule of Borrowings and Other Debt Obligation | The following tables present information regarding SC's secured structured financings as of June 30, 2016 and December 31, 2015: June 30, 2016 Balance Initial Note Amounts Issued Initial Weighted Average Interest Rate Range Collateral Restricted Cash (dollars in thousands)SC public securitizations, maturing on various dates(1)$14,202,169 $30,001,112  0.89% - 2.46%  $18,399,755 $1,457,747SC privately issued amortizing notes, maturing on various dates(1)8,303,636 13,035,991  0.88% - 2.86%  11,763,437 494,816     Total SC secured structured financings$22,505,805 $43,037,103  0.88% - 2.86%  $30,163,192 $1,952,563(1)  SC has entered into various securitization transactions involving its retail automotive installment loans and leases. These transactions are accounted for as secured financings and therefore both the securitized RICs, and the related securitization debt issued by SPEs, remain on the Condensed Consolidated Balance Sheets. The maturity of this debt is based on the timing of repayments from the securitized assets.NOTE 10. BORROWINGS (continued) December 31, 2015 Balance Initial Note Amounts Issued Initial Weighted Average Interest Rate Range Collateral Restricted Cash (dollars in thousands)SC public securitizations, maturing on various dates(1)$12,679,987 $24,923,292 0.89% - 2.29% $16,256,067 $1,242,857SC privately issued amortizing notes, maturing on various dates(1)8,213,217 11,729,171 0.88% - 2.81% 11,495,352 457,840     Total SC secured structured financings$20,893,204 $36,652,463 0.88% - 2.81% $27,751,419 $1,700,697(1)  SC has entered into various securitization transactions involving its retail automotive installment loans and leases. These transactions are accounted for as secured financings and therefore both the securitized RICs, and the related securitization debt issued by SPEs, remain on the Condensed Consolidated Balance Sheets. The maturity of this debt is based on the timing of repayments from the securitized assets.The following tables present information regarding SC's credit facilities as of June 30, 2016 and December 31, 2015: June 30, 2016 Balance EffectiveRate Assets Pledged Restricted Cash Pledged (dollars in thousands)Warehouse line, maturing on various dates(1)$449,585 2.27% $621,893 $18,030Warehouse line, due July 2016(2)266,084 1.72% 371,360 —Warehouse line, due November 2016(3)175,000 2.00% — —Warehouse line, due November 2016(3)250,000 2.00% — 2,502Warehouse line, due June 2017124,396 3.10% 300,020 25,055Warehouse line, due July 2017(4)843,820 1.49% 957,299 26,983Warehouse line, due July 2017(5)2,775,843 1.44% 4,234,607 60,400Warehouse line, due December 2017576,777 2.39% 821,314 26,889Warehouse line, due January 201891,500 3.08% 127,284 4,167Warehouse line, due March 2018(6)428,899 1.52% 609,417 18,123Repurchase facility, due May 2017(7)787,703 2.71% — 31,763Repurchase facility, due April 2017(7)235,509 1.79% — —Line of credit with related party, due December 2016(8)1,000,000 2.71% — —Line of credit with related party, due December 2016(8)500,000 2.75% — —Line of credit with related party, due December 2018(8)550,000 2.80% — —     Total SC revolving credit facilities$9,055,116 2.04% $8,043,194 $213,912(1)  As of June 30, 2016, half of the outstanding balance on this facility matures in March 2017 and half matures in March 2018. (2)  As of December 31, 2015 this warehouse line was due in June 2016. It was subsequently amended in July 2016 to extend the maturity to January 2018.(3)  These lines are collateralized by residuals retained by SC.(4)  This line is held exclusively for financing Chrysler Capital loans.(5)  This line is held exclusively for financing Chrysler Capital leases.(6)  As of December 31, 2015 this warehouse line was due in September 2017.(7)  This repurchase facility is collateralized by securitization notes payable retained by SC. No portion of this facility is unsecured. These facilities have rolling maturities up to 180 days.(8)  These lines are also collateralized by securitization notes payable and residuals retained by SC. As of June 30, 2016, $1.4 billion of the aggregate outstanding balances on these credit facilities was unsecured. NOTE 10. BORROWINGS (continued) December 31, 2015 Balance EffectiveRate Assets Pledged Restricted Cash Pledged (dollars in thousands)Warehouse line, maturing on various dates(1)$808,135 1.29% $1,137,257 $24,942Warehouse line, due June 2016378,301 1.48% 535,737 —Warehouse line, due November 2016(2)175,000 1.90% — —Warehouse line, due November 2016(2)250,000 1.90% — 2,501Warehouse line, due July 2017(3)682,720 1.35% 809,185 20,852Warehouse line, due July 2017(4)2,247,443 1.41% 3,412,321 48,589Warehouse line, due September 2017565,399 1.20% 824,327 15,759Warehouse line, due December 2017 (5)944,877 1.56% 1,345,051 32,038Repurchase facility, due December 2016(6)850,904 2.07% — 34,166Line of credit with related party, due December 2016(7)1,000,000 2.61% — —Line of credit with related party, due December 2016(7)500,000 2.65% — —Line of credit with related party, due December 2018(7)800,000 2.84% — —     Total SC revolving credit facilities$9,202,779 1.81% $8,063,878 $178,847(1)  As of June 30, 2016, half of the outstanding balance on this facility matures in March 2017 and half matures in March 2018. (2)  These lines are collateralized by residuals retained by SC.(3)  This line is held exclusively for financing Chrysler Capital loans.(4)  This line is held exclusively for financing Chrysler Capital leases.(5)  In December 2015, the commitment on this warehouse line was amended to extend the commitment termination date to December 2017.(6)  This repurchase facility is collateralized by securitization notes payable retained by SC. No portion of this facility is unsecured. This facility has rolling 30-day and 180-day maturities.(7)  These lines are also collateralized by securitization notes payable and residuals retained by SC. As of June 30, 2016, $1.4 billion of the aggregate outstanding balances on these credit facilities was unsecured. |

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| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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| - Definition
Tabular disclosure of information pertaining to short-term and long-debt instruments or arrangements, including but not limited to identification of terms, features, collateral requirements and other information necessary to a fair presentation.
+ References
No definition available.
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