Fair Value Measurements - Changes in balances of Level 3 financial assets carried at fair value (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	$ 926	$ 3,706
Total realized/unrealized gains (losses) included in Net income	23	126
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(21)	(45)
Purchases and issuances	105	351
Sales and settlements	(27)	(247)
Transfer into Level 3	37	51
Transfer out of Level 3	(45)	(293)
Financial assets, Ending Balance	998	3,649
Fixed maturities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	600	538
Total realized/unrealized gains (losses) included in Net income	2	(1)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(21)	(2)
Purchases and issuances	75	142
Sales and settlements	(24)	(42)
Transfer into Level 3	34	19
Transfer out of Level 3	(41)	(52)
Financial assets, Ending Balance	625	602
U.S. government agency
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	0
Total realized/unrealized gains (losses) included in Net income	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases and issuances	0	0
Sales and settlements	0	0
Transfer into Level 3	0	0
Transfer out of Level 3	0	0
Financial assets, Ending Balance	0	0
State and municipal
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	41	39
Total realized/unrealized gains (losses) included in Net income	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(2)	0
Purchases and issuances	0	0
Sales and settlements	(1)	0
Transfer into Level 3	0	0
Transfer out of Level 3	(5)	0
Financial assets, Ending Balance	33	39
Residential MBS
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	14	38
Total realized/unrealized gains (losses) included in Net income	0	(3)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases and issuances	0	6
Sales and settlements	(1)	0
Transfer into Level 3	0	3
Transfer out of Level 3	(2)	(17)
Financial assets, Ending Balance	11	27
Commercial MBS
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	2
Total realized/unrealized gains (losses) included in Net income	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases and issuances	0	0
Sales and settlements	0	0
Transfer into Level 3	0	0
Transfer out of Level 3	0	(2)
Financial assets, Ending Balance	0	0
Collateralized loan obligations
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	16
Total realized/unrealized gains (losses) included in Net income	0	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	(1)
Purchases and issuances	0	0
Sales and settlements	0	(1)
Transfer into Level 3	0	0
Transfer out of Level 3	0	(9)
Financial assets, Ending Balance	0	6
Other asset-backed securities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	278	305
Total realized/unrealized gains (losses) included in Net income	2	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(9)	0
Purchases and issuances	47	52
Sales and settlements	(15)	(23)
Transfer into Level 3	34	14
Transfer out of Level 3	0	(22)
Financial assets, Ending Balance	337	326
Corporate and other
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	267	138
Total realized/unrealized gains (losses) included in Net income	0	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(10)	(1)
Purchases and issuances	28	84
Sales and settlements	(7)	(18)
Transfer into Level 3	0	2
Transfer out of Level 3	(34)	(2)
Financial assets, Ending Balance	244	204
Equity securities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	313	176
Total realized/unrealized gains (losses) included in Net income	22	53
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases and issuances	30	12
Sales and settlements	(3)	(14)
Transfer into Level 3	3	0
Transfer out of Level 3	(4)	0
Financial assets, Ending Balance	361	227
Assets of MIE
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	13	21
Total realized/unrealized gains (losses) included in Net income	(1)	4
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases and issuances	0	1
Sales and settlements	0	0
Transfer into Level 3	0	0
Transfer out of Level 3	0	(12)
Financial assets, Ending Balance	$ 12	14
Assets of discontinued annuity operations | Annuity subsidiaries
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance		2,971
Total realized/unrealized gains (losses) included in Net income		70
Total realized/unrealized gains (losses) included in other comprehensive income (loss)		(43)
Purchases and issuances		196
Sales and settlements		(191)
Transfer into Level 3		32
Transfer out of Level 3		(229)
Financial assets, Ending Balance		$ 2,806