v2.4.0.8

Fair Value Measurements (Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value) (Detail) (USD $) In Millions, unless otherwise specified | Sep. 30, 2014 | Dec. 31, 2013
--- | --- | ---
Financial Instruments Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | $ 7,763 | $ 6,263
Partially-owned insurance companies | 495 | 470
Total assets | 8,258 | 6,733
Short-term debt | 1,864 | 1,913
Long-term debt | 4,349 | 4,088
Trust preferred securities | 459 | 438
Total liabilities | 6,672 | 6,439
Financial Instruments Fair Value [Member] | U.S. Treasury And Agency [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 817 | 832
Financial Instruments Fair Value [Member] | Foreign [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 978 | 897
Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,525 | 2,005
Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,130 | 1,379
Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 1,313 | 1,150
Fair Value, Inputs, Level 1 [Member] | Financial Instruments Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 625 | 596
Total assets | 625 | 596
Fair Value, Inputs, Level 1 [Member] | Financial Instruments Fair Value [Member] | U.S. Treasury And Agency [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 625 | 596
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 7,123 | 5,652
Total assets | 7,123 | 5,652
Short-term debt | 1,864 | 1,913
Long-term debt | 4,349 | 4,088
Trust preferred securities | 459 | 438
Total liabilities | 6,672 | 6,439
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] | U.S. Treasury And Agency [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 192 | 236
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] | Foreign [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 978 | 897
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,510 | 1,990
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,130 | 1,379
Fair Value, Inputs, Level 2 [Member] | Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 1,313 | 1,150
Fair Value, Inputs, Level 3 [Member] | Financial Instruments Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 15 | 15
Partially-owned insurance companies | 495 | 470
Total assets | 510 | 485
Fair Value, Inputs, Level 3 [Member] | Financial Instruments Fair Value [Member] | U.S. Treasury And Agency [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 0 | 0
Fair Value, Inputs, Level 3 [Member] | Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 15 | 15
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 7,548 | 6,098
Partially-owned insurance companies | 495 | 470
Total assets | 8,043 | 6,568
Short-term debt | 1,851 | 1,901
Long-term debt | 4,057 | 3,807
Trust preferred securities | 309 | 309
Total liabilities | 6,217 | 6,017
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] | U.S. Treasury And Agency [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 804 | 820
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] | Foreign [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 937 | 864
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] | Corporate Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,443 | 1,922
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] | Collateralized Mortgage Backed Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | 2,087 | 1,341
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Financial Instruments Carrying Value [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total Fixed maturities held to maturity | $ 1,277 | $ 1,151

X
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