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Investments (Distribution Of Securities By Percentage Of Fair Value Below Book Value By More Than 5% For A Continuous Twelve Month Period Or Longer) (Detail) - Unrealized loss position > 12 months $ in Millions | Mar. 31, 2020 USD ($) security
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> 5% To 15% [Member] |
Available For Sale Securities [Abstract] |
Number of available-for-sale securities in unrealized loss position | security | 8
Fixed-maturity securities held as available-for-sale, amortized cost | $ 21
Available For Sale Securities | $ 20
Held To Maturity Securities [Abstract] |
Percentage Of Fair Value Below Book Value Minimum | 5.00%
Percentage Of Fair Value Below Book Value Maximum | 15.00%
> 15% To 25% [Member] |
Available For Sale Securities [Abstract] |
Number of available-for-sale securities in unrealized loss position | security | 18
Fixed-maturity securities held as available-for-sale, amortized cost | $ 48
Available For Sale Securities | $ 38
Held To Maturity Securities [Abstract] |
Percentage Of Fair Value Below Book Value Minimum | 15.00%
Percentage Of Fair Value Below Book Value Maximum | 25.00%
> 25% To 50% [Member] |
Available For Sale Securities [Abstract] |
Number of available-for-sale securities in unrealized loss position | security | 13
Fixed-maturity securities held as available-for-sale, amortized cost | $ 33
Available For Sale Securities | $ 21
Held To Maturity Securities [Abstract] |
Percentage Of Fair Value Below Book Value Minimum | 25.00%
Percentage Of Fair Value Below Book Value Maximum | 50.00%
> 50% [Member] |
Available For Sale Securities [Abstract] |
Number of available-for-sale securities in unrealized loss position | security | 2
Fixed-maturity securities held as available-for-sale, amortized cost | $ 0
Available For Sale Securities | $ 0
Held To Maturity Securities [Abstract] |
Percentage Of Fair Value Below Book Value Minimum | 50.00%
Greater Than 5% [Member] |
Available For Sale Securities [Abstract] |
Number of available-for-sale securities in unrealized loss position | security | 41
Fixed-maturity securities held as available-for-sale, amortized cost | $ 102
Available For Sale Securities | $ 79

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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
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- Definition Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563 + Details
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