Fair Value of Assets and Liabilities - Rollforward of level 3 assets and liabilities held at fair value on a recurring basis during the period (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Assets
Balance at beginning of period	$ 676	$ 727	$ 565	$ 832
Total gains (losses) included in: net income	(19)	33	73	68
Total gains (losses) included in: OCI	(1)	0	(6)	0
Transfers into Level 3	2	1	2	13
Transfers out of Level 3	(1)	(42)	(28)	(45)
Transfers to (from) held for sale		0		0
Purchases	56	150	168	236
Sales	(66)	(95)	(101)	(265)
Issues	0	0	0	0
Settlements	(2)	(37)	(28)	(102)
Balance at end of period	645	737	645	737
Liabilities
Balance at the beginning of the period	0	(490)	0	(516)
Total gains (losses) included in: net income	0	15	0	46
Total gains (losses) included in: OCI	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers to (from) held for sale		0		0
Purchases		0	0	0
Sales	0	0	0	0
Issues	0	(9)	0	(25)
Settlements	0	5	0	16
Balance at the end of the period	0	(479)	0	(479)
Net investment income
Total Level 3 gains (losses) included in net income
Gain (loss) included in earnings	4	6	17	(1)
Net gains (losses) on investments and derivatives
Total Level 3 gains (losses) included in net income
Gain (loss) included in earnings	(23)	26	56	66
Liabilities held for sale
Liabilities
Balance at the beginning of the period		(490)		(516)
Total gains (losses) included in: net income	0	15	0	46
Total gains (losses) included in: OCI		0		0
Transfers into Level 3		0		0
Transfers out of Level 3		0		0
Transfers to (from) held for sale		0		0
Purchases		0		0
Sales		0		0
Issues		(9)		(25)
Settlements		5		16
Balance at the end of the period		(479)		(479)
Municipal
Assets
Balance at beginning of period	18	18	18	17
Total gains (losses) included in: net income	0	0	0	0
Total gains (losses) included in: OCI	0	(1)	1	0
Transfers into Level 3	2	0	2	0
Transfers out of Level 3	(1)	0	0	0
Transfers to (from) held for sale		0		0
Purchases	0	0	0	3
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	0	0	(2)	(3)
Balance at end of period	19	17	19	17
Corporate - public
Assets
Balance at beginning of period	77	20	20	67
Total gains (losses) included in: net income	0	0	0	1
Total gains (losses) included in: OCI	(2)	0	(6)	(2)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers to (from) held for sale		(1)		(7)
Purchases	0	0	66	13
Sales	(7)	0	(10)	(53)
Issues	0	0	0	0
Settlements	0	0	(2)	0
Balance at end of period	68	19	68	19
Corporate - privately placed
Assets
Balance at beginning of period	73	84	66	63
Total gains (losses) included in: net income	1	1	20	0
Total gains (losses) included in: OCI	1	1	(1)	2
Transfers into Level 3	0	0	0	8
Transfers out of Level 3	0	(22)	0	0
Transfers to (from) held for sale		(2)		14
Purchases	18	104	32	103
Sales	(22)	(7)	(46)	(31)
Issues	0	0	0	0
Settlements	0	(5)	0	(5)
Balance at end of period	71	154	71	154
ABS
Assets
Balance at beginning of period	18	33	40	79
Total gains (losses) included in: net income	0	0	1	1
Total gains (losses) included in: OCI	0	0	0	0
Transfers into Level 3	0	1	0	0
Transfers out of Level 3	0	0	(28)	(32)
Transfers to (from) held for sale		0		0
Purchases	30	5	37	57
Sales	0	0	0	(42)
Issues	0	0	0	0
Settlements	0	(30)	(2)	(54)
Balance at end of period	48	9	48	9
Fixed income securities
Assets
Balance at beginning of period	186	155	144	226
Total gains (losses) included in: net income	1	1	21	2
Total gains (losses) included in: OCI	(1)	0	(6)	0
Transfers into Level 3	2	1	2	8
Transfers out of Level 3	(1)	(22)	(28)	(32)
Transfers to (from) held for sale		(3)		7
Purchases	48	109	135	176
Sales	(29)	(7)	(56)	(126)
Issues	0	0	0	0
Settlements	0	(35)	(6)	(62)
Balance at end of period	206	199	206	199
Equity securities
Assets
Balance at beginning of period	372	405	349	304
Total gains (losses) included in: net income	(16)	31	13	63
Total gains (losses) included in: OCI	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers to (from) held for sale		0		101
Purchases	8	27	10	40
Sales	(37)	(87)	(45)	(132)
Issues	0	0	0	0
Settlements	0	0	0	0
Balance at end of period	327	376	327	376
Short-term investments
Assets
Balance at beginning of period	8	0	5	35
Total gains (losses) included in: net income	0	0	0	0
Total gains (losses) included in: OCI	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers to (from) held for sale		0		0
Purchases	0	14	23	14
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(2)	0	(22)	(35)
Balance at end of period	6	14	6	14
Other investments
Assets
Balance at beginning of period	2	3	2	0
Total gains (losses) included in: net income	0	0	0	0
Total gains (losses) included in: OCI	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers to (from) held for sale		0		0
Purchases	0	0	0	3
Sales	0	(1)	0	(1)
Issues	0	0	0	0
Settlements	0	0	0	0
Balance at end of period	2	2	2	2
Other assets
Assets
Balance at beginning of period	108		65
Total gains (losses) included in: net income	(4)		39
Total gains (losses) included in: OCI	0		0
Transfers into Level 3	0		0
Transfers out of Level 3	0		0
Purchases	0		0
Sales	0		0
Issues	0		0
Settlements	0		0
Balance at end of period	$ 104		$ 104
Assets held for sale
Assets
Balance at beginning of period		164		267
Total gains (losses) included in: net income		1		3
Total gains (losses) included in: OCI		0		0
Transfers into Level 3		0		5
Transfers out of Level 3		(20)		(13)
Transfers to (from) held for sale		3		(108)
Purchases		0		3
Sales		0		(6)
Issues		0		0
Settlements		(2)		(5)
Balance at end of period		$ 146		$ 146