Investments - Analysis of Cost or Amortized Cost, Gross Unrealized Gains and Losses and Fair Value for Investments (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale
Total	$ 12,330	$ 12,230
Fixed maturities, at fair value	12,376	13,022
Debt Securities
Debt Securities, Available-for-sale
Total	12,330	12,230
Gross unrealized gain	291	808
Gross unrealized loss	245	16
Fixed maturities, at fair value	12,376	13,022
Debt Securities \| Corporate
Debt Securities, Available-for-sale
Total	7,131	7,043
Gross unrealized gain	184	467
Gross unrealized loss	166	13
Fixed maturities, at fair value	7,149	7,497
Debt Securities \| States, municipalities and political subdivisions
Debt Securities, Available-for-sale
Total	4,780	4,768
Gross unrealized gain	106	330
Gross unrealized loss	76	3
Fixed maturities, at fair value	4,810	5,095
Debt Securities \| Commercial mortgage-backed
Debt Securities, Available-for-sale
Total	267	264
Gross unrealized gain	1	9
Gross unrealized loss	2	0
Fixed maturities, at fair value	266	273
Debt Securities \| United States government
Debt Securities, Available-for-sale
Total	113	121
Gross unrealized gain	0	2
Gross unrealized loss	1	0
Fixed maturities, at fair value	112	123
Debt Securities \| Foreign government
Debt Securities, Available-for-sale
Total	25	26
Gross unrealized gain	0	0
Gross unrealized loss	0	0
Fixed maturities, at fair value	25	26
Debt Securities \| Government-sponsored enterprises
Debt Securities, Available-for-sale
Total	14	8
Gross unrealized gain	0	0
Gross unrealized loss	0	0
Fixed maturities, at fair value	$ 14	$ 8

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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