Fair Value Measurements - Changes in balances of Level 3 financial assets carried at fair value (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	$ 998	$ 3,649	$ 926	$ 3,706
Total realized/unrealized gains (losses) included in Net income	(1)	30	22	156
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(12)	22	(33)	(22)
Purchases and issuances	64	86	169	437
Sales and settlements	(32)	(196)	(59)	(444)
Transfer into Level 3	2	5	39	56
Transfer out of Level 3	(36)	(12)	(81)	(305)
Sale of annuity business		(2,719)		(2,719)
Financial assets, Ending Balance	983	865	983	865
Fixed maturities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	625	602	600	538
Total realized/unrealized gains (losses) included in Net income	0	(2)	2	(3)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(12)	1	(33)	(1)
Purchases and issuances	42	60	117	202
Sales and settlements	(30)	(55)	(54)	(97)
Transfer into Level 3	2	4	36	23
Transfer out of Level 3	(34)	(5)	(75)	(57)
Sale of annuity business		0		0
Financial assets, Ending Balance	593	605	593	605
U.S. government agency
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	0	0	0
Total realized/unrealized gains (losses) included in Net income	0	0	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	0	0	0	0
Sales and settlements	0	0	0	0
Transfer into Level 3	0	0	0	0
Transfer out of Level 3	0	0	0	0
Sale of annuity business		0		0
Financial assets, Ending Balance	0	0	0	0
State and municipal
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	33	39	41	39
Total realized/unrealized gains (losses) included in Net income	0	0	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(1)	0	(3)	0
Purchases and issuances	0	0	0	0
Sales and settlements	0	(3)	(1)	(3)
Transfer into Level 3	0	0	0	0
Transfer out of Level 3	(31)	0	(36)	0
Sale of annuity business		0		0
Financial assets, Ending Balance	1	36	1	36
Residential MBS
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	11	27	14	38
Total realized/unrealized gains (losses) included in Net income	0	0	0	(3)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	0	0	0	6
Sales and settlements	0	(1)	(1)	(1)
Transfer into Level 3	0	3	0	6
Transfer out of Level 3	(3)	(1)	(5)	(18)
Sale of annuity business		0		0
Financial assets, Ending Balance	8	28	8	28
Commercial MBS
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	0	0	2
Total realized/unrealized gains (losses) included in Net income	0	0	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	0	0	0	0
Sales and settlements	0	0	0	0
Transfer into Level 3	0	0	0	0
Transfer out of Level 3	0	0	0	(2)
Sale of annuity business		0		0
Financial assets, Ending Balance	0	0	0	0
Collateralized loan obligations
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	0	6	0	16
Total realized/unrealized gains (losses) included in Net income	0	0	0	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	(1)
Purchases and issuances	0	0	0	0
Sales and settlements	0	0	0	(1)
Transfer into Level 3	2	0	2	0
Transfer out of Level 3	0	0	0	(9)
Sale of annuity business		0		0
Financial assets, Ending Balance	2	6	2	6
Other asset-backed securities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	337	326	278	305
Total realized/unrealized gains (losses) included in Net income	0	0	2	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(7)	1	(16)	1
Purchases and issuances	10	38	57	90
Sales and settlements	(27)	(49)	(42)	(72)
Transfer into Level 3	0	0	34	14
Transfer out of Level 3	0	(1)	0	(23)
Sale of annuity business		0		0
Financial assets, Ending Balance	313	315	313	315
Corporate and other
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	244	204	267	138
Total realized/unrealized gains (losses) included in Net income	0	(2)	0	(1)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(4)	0	(14)	(1)
Purchases and issuances	32	22	60	106
Sales and settlements	(3)	(2)	(10)	(20)
Transfer into Level 3	0	1	0	3
Transfer out of Level 3	0	(3)	(34)	(5)
Sale of annuity business		0		0
Financial assets, Ending Balance	269	220	269	220
Equity securities
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	361	227	313	176
Total realized/unrealized gains (losses) included in Net income	0	18	22	71
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	21	12	51	24
Sales and settlements	(2)	(5)	(5)	(19)
Transfer into Level 3	0	0	3	0
Transfer out of Level 3	(2)	(7)	(6)	(7)
Sale of annuity business		0		0
Financial assets, Ending Balance	378	245	378	245
Assets of MIE
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance	12	14	13	21
Total realized/unrealized gains (losses) included in Net income	(1)	(1)	(2)	3
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	1	1	1	2
Sales and settlements	0	0	0	0
Transfer into Level 3	0	1	0	1
Transfer out of Level 3	0	0	0	(12)
Sale of annuity business		0		0
Financial assets, Ending Balance	$ 12	15	$ 12	15
Assets of discontinued annuity operations | Annuity subsidiaries
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Financial assets, Beginning Balance		2,806		2,971
Total realized/unrealized gains (losses) included in Net income		15		85
Total realized/unrealized gains (losses) included in other comprehensive income (loss)		21		(21)
Purchases and issuances		13		209
Sales and settlements		(136)		(328)
Transfer into Level 3		0		32
Transfer out of Level 3		0		(229)
Sale of annuity business		(2,719)		(2,719)
Financial assets, Ending Balance		$ 0		$ 0