Changes in and Reclassifications From Accumulated Other Comprehensive Income (Loss) - AOCI Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 18,556	$ 16,270
OCI, net of tax	(998)	1,118	$ 1,631
Ending balance	17,843	18,556	16,270
Net Unrealized Gain on Fixed Maturities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,834	1,684	24
OCI, before Reclassifications, before Tax, Attributable to Parent	(1,307)	1,627	2,275
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	234	171	174
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(1,541)	1,456	2,101
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	323	(306)	(441)
OCI, net of tax	(1,218)	1,150	1,660
Ending balance	1,616	2,834	1,684
AOCI, Gain (Loss), Debt Securities, Available-for-sale, with Allowance for Credit Loss, Parent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(2)	(3)	(4)
OCI, before Reclassifications, before Tax, Attributable to Parent	0	1	1
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	0	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	0	1	1
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	0	0	0
OCI, net of tax	0	1	1
Ending balance	(2)	(2)	(3)
Net Gain (Loss) on Cash Flow Hedging Instruments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	12	9	(5)
OCI, before Reclassifications, before Tax, Attributable to Parent	28	30	28
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	36	26	10
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(8)	4	18
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	2	(1)	(4)
OCI, net of tax	(6)	3	14
Ending balance	6	12	9
Foreign Currency Translation Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	43	34	30
OCI, before Reclassifications, before Tax, Attributable to Parent	(3)	11	5
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	0	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(3)	11	5
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	1	(2)	(1)
OCI, net of tax	(2)	9	4
Ending balance	41	43	34
Pension and Other Postretirement Plan Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,717)	(1,672)	(1,624)
OCI, before Reclassifications, before Tax, Attributable to Parent	219	(117)	(104)
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	(70)	(60)	(43)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	289	(57)	(61)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	(61)	12	13
OCI, net of tax	228	(45)	(48)
Ending balance	(1,489)	(1,717)	(1,672)
AOCI, net of tax
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,170	52	(1,579)
OCI, before Reclassifications, before Tax, Attributable to Parent	(1,063)	1,552	2,205
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	200	137	141
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(1,263)	1,415	2,064
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	265	(297)	(433)
OCI, net of tax	(998)	1,118	1,631
Ending balance	$ 172	$ 1,170	$ 52

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Amount before tax of other comprehensive income (loss) attributable to parent entity.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss) attributable to parent entity.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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