| **Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)In Thousands, unless otherwise specified** | 3 Months Ended                                                                                     | 9 Months Ended |
|---------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------|----------------|
||
| **Statement of Comprehensive Income [Abstract]**                                                                          |                                                                                               |                |   |   |  |   |
| NET INCOME INCLUDING NONCONTROLLING INTEREST                                                                              | $ 259,092us-gaap_ProfitLoss                                                                        |                | $ 76,708us-gaap_ProfitLoss | $ 2,476,050us-gaap_ProfitLoss |  | $ 550,134us-gaap_ProfitLoss |
| **OTHER COMPREHENSIVE INCOME/LOSS, NET OF TAX**                                                                           |                                                                                               |                |   |   |  |   |
| Net unrealized gains on cash flow hedge derivative financial instruments                                                  | 17,381us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax                    |                | 6,171us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax | 24,022us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax |  | 31,225us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax |
| Net unrealized gains/(losses) on investment securities                                                                    | (17,697)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax           |                | (18,463)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax | 111,291us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax |  | (291,331)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax |
| Pension and post-retirement actuarial gain                                                                                | 272us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax | [1]            | 549us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax | 1,107us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax | [1] | 1,647us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax |
| TOTAL OTHER COMPREHENSIVE (LOSS)                                                                                          | (44)us-gaap_OtherComprehensiveIncomeLossNetOfTax                                                   |                | (11,743)us-gaap_OtherComprehensiveIncomeLossNetOfTax | 136,420us-gaap_OtherComprehensiveIncomeLossNetOfTax |  | (258,459)us-gaap_OtherComprehensiveIncomeLossNetOfTax |
| COMPREHENSIVE INCOME/LOSS                                                                                                 | 259,048us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest     |                | 64,965us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest | 2,612,470us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest |  | 291,675us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest |
| COMPREHENSIVE INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                                                              | 54,420us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest                      |                | 0us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest | 298,633us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest |  | 0us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest |
| COMPREHENSIVE INCOME ATTRIBUTABLE TO SHUSA                                                                                | $ 204,628us-gaap_ComprehensiveIncomeNetOfTax                                                       |                | $ 64,965us-gaap_ComprehensiveIncomeNetOfTax | $ 2,313,837us-gaap_ComprehensiveIncomeNetOfTax |  | $ 291,675us-gaap_ComprehensiveIncomeNetOfTax |
|                                                                                                                           |
| [1]Included in the computation of net periodic pension costs.                                                             |

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| - Definition
Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.
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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.
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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.
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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.
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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).
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Amount after tax and reclassification adjustments of other comprehensive income (loss).
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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.
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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.
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