| **Summary Of Investments Other Than Investments In Related Parties**             | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| **Summary of Investments, Other than Investments in Related Parties [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Summary Of Investments Other Than Investments In Related Parties                 | Schedule ICincinnati Financial Corporation and SubsidiariesSummary of Investments - Other Than Investments in Related Parties(Dollars in millions) At December 31, 2014Type of investment Cost oramortized cost Fairvalue Balance sheetFixed maturities:      States, municipalities and political subdivisions:      The Cincinnati Insurance Company $2,634 $2,759 $2,759The Cincinnati Casualty Company 136 143 143The Cincinnati Indemnity Company 39 41 41The Cincinnati Life Insurance Company 187 213 213The Cincinnati Specialty Underwriters Insurance Company 270 286 286CSU Producer Resources Inc. 1 1 1Total 3,267 3,443 3,443Convertibles and bonds with warrants attached:      The Cincinnati Insurance Company 7 7 7Total 7 7 7United States government:      The Cincinnati Insurance Company 1 1 1The Cincinnati Casualty Company 2 2 2The Cincinnati Indemnity Company 1 1 1The Cincinnati Life Insurance Company 3 3 3Total 7 7 7Government-sponsored enterprises:      The Cincinnati Life Insurance Company 209 204 204The Cincinnati Insurance Company 4 4 4Total 213 208 208Foreign government:      The Cincinnati Insurance Company 10 10 10Total 10 10 10All other corporate bonds:      The Cincinnati Insurance Company 2,507 2,706 2,706The Cincinnati Casualty Company 110 118 118The Cincinnati Indemnity Company 21 23 23The Cincinnati Specialty Underwriters Insurance Company 151 159 159The Cincinnati Life Insurance Company 2,517 2,706 2,706CSU Producer Resources Inc. 4 4 4Cincinnati Financial Corporation 57 69 69Total 5,367 5,785 5,785Total fixed maturities $8,871 $9,460 $9,460        Schedule I (continued)Cincinnati Financial Corporation and SubsidiariesSummary of Investments - Other Than Investments in Related Parties(Dollars in millions) At December 31, 2014Type of investment Cost oramortized cost Fairvalue Balance sheetEquity securities:      Common equities:      The Cincinnati Insurance Company $1,462 $2,831 $2,831The Cincinnati Casualty Company 45 91 91The Cincinnati Indemnity Company 12 22 22The Cincinnati Specialty Underwriters Insurance Company 51 85 85CSU Producer Resources Inc. 9 11 11Cincinnati Financial Corporation 1,004 1,639 1,639Total 2,583 4,679 4,679Nonredeemable preferred equities:      The Cincinnati Insurance Company 137 167 167The Cincinnati Life Insurance Company 5 8 8Cincinnati Financial Corporation 3 4 4Total 145 179 179Total equity securities $2,728 $4,858 $4,858Other invested assets:      Policy loans:      The Cincinnati Life Insurance Company $31 — $31Private equity:      Cincinnati Financial Corporation 37 — 37Total other invested assets $68 — $68Total investments $11,667 — $14,386        |

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| - Definition
The entire disclosure for the schedule applicable to insurance companies summarizing investments held as of the most recent audited balance sheet. At a minimum, such summary is by three major categories of investments including: (1) fixed maturities primarily consisting of bonds, including convertibles and bonds with warrants, and redeemable preferred stocks, (2) equity securities primarily consisting of common stocks and nonredeemable preferred stocks, and (3) other investments including mortgage loans on real estate, real estate held for investment, real estate acquired in satisfaction of debt, policy loans, other long-term investments, and short-term investments not otherwise categorized. The information provided with respect to each item within each category includes: (A) the original cost of equity securities and, as to fixed maturity securities, original cost reduced by repayments and adjusted for amortization of premiums or accrual of discounts, (B) fair value as of the reporting date, and (C) the amount at which the item within each category is shown in the statement of financial position; with respect to (C), if the amount at which shown in the statement of financial position is different from the items original [amortized] cost or fair value, an explanation of the difference may be included herein.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 15 -Article 12Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 7 -Subparagraph (SX 210.12-15) -URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611379-123010
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