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	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Balance at beginning of period	$ 565	$ 832	$ 738
Total gains (losses) included in: net income	76	128	0
Total gains (losses) included in: OCI	(2)	2	(12)
Transfers into Level 3	2	32	128
Transfers out of Level 3	(28)	(45)	(116)
Purchases	155	124	240
Sales	(121)	(405)	(95)
Issues	0	0	0
Settlements	(29)	(103)	(51)
Balance at end of period	$ 618	$ 565	$ 832
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment income, Net gains (losses) on investments and derivatives	Net investment income, Net gains (losses) on investments and derivatives	Net investment income, Net gains (losses) on investments and derivatives
Liabilities
Balance at beginning of period	$ 0	$ (516)	$ (462)
Total gains (losses) included in: net income	0	35	(43)
Total gains (losses) included in: OCI	0	0	0
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Purchases	0	0	0
Sales	0	492	0
Issues	0	(28)	(34)
Settlements	0	17	23
Balance at end of period	0	0	(516)
Net investment income
Fair value assets and liabilities measured on recurring basis, gain (loss) included in earnings
Gain (loss) included in earnings	$ 15	$ 1	$ (16)
Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment income	Net investment income	Net investment income
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment income	Net investment income	Net investment income
Net gains (losses) on investments and derivatives
Fair value assets and liabilities measured on recurring basis, gain (loss) included in earnings
Gain (loss) included in earnings	$ 61	$ 124	$ 15
Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives
Liabilities held for sale
Liabilities
Balance at beginning of period	$ 0	$ (516)	$ (462)
Total gains (losses) included in: net income		35	(43)
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		492	0
Issues		(28)	(34)
Settlements		17	23
Balance at end of period		0	(516)
Municipal
Assets
Balance at beginning of period	18	17	22
Total gains (losses) included in: net income	0	0	0
Total gains (losses) included in: OCI	1	0	0
Transfers into Level 3	2	1	0
Transfers out of Level 3	0	0	0
Purchases	2	3	0
Sales	0	0	(3)
Issues	0	0	0
Settlements	(2)	(3)	(2)
Balance at end of period	21	18	17
Corporate - public
Assets
Balance at beginning of period	20	67	36
Total gains (losses) included in: net income	0	1	0
Total gains (losses) included in: OCI	(5)	(1)	1
Transfers into Level 3	0	0	1
Transfers out of Level 3	0	0	0
Purchases	66	13	48
Sales	(10)	(53)	(19)
Issues	0	0	0
Settlements	(2)	0	0
Balance at end of period	69	20	67
Corporate - privately placed
Assets
Balance at beginning of period	66	63	32
Total gains (losses) included in: net income	19	(2)	0
Total gains (losses) included in: OCI	2	3	(5)
Transfers into Level 3	0	10	21
Transfers out of Level 3	0	0	0
Purchases	34	6	17
Sales	(65)	(23)	(2)
Issues	0	0	0
Settlements	(1)	(5)	0
Balance at end of period	55	66	63
ABS
Assets
Balance at beginning of period	40	79	84
Total gains (losses) included in: net income	1	0	(1)
Total gains (losses) included in: OCI	0	1	0
Transfers into Level 3	0	4	54
Transfers out of Level 3	(28)	(32)	(49)
Purchases	17	47	59
Sales	0	(5)	(26)
Issues	0	0	0
Settlements	(2)	(54)	(42)
Balance at end of period	28	40	79
Fixed income securities
Assets
Balance at beginning of period	144	226	174
Total gains (losses) included in: net income	20	(1)	(1)
Total gains (losses) included in: OCI	(2)	3	(4)
Transfers into Level 3	2	15	76
Transfers out of Level 3	(28)	(32)	(49)
Purchases	119	69	124
Sales	(75)	(81)	(50)
Issues	0	0	0
Settlements	(7)	(62)	(44)
Balance at end of period	173	144	226
Equity securities
Assets
Balance at beginning of period	349	304	255
Total gains (losses) included in: net income	16	61	0
Total gains (losses) included in: OCI	0	0	0
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Purchases	13	43	57
Sales	(45)	(160)	(8)
Issues	0	0	0
Settlements	0	0	0
Balance at end of period	333	349	304
Short-term investments
Assets
Balance at beginning of period	5	35	25
Total gains (losses) included in: net income	0	0	0
Total gains (losses) included in: OCI	0	0	0
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	(25)
Purchases	23	5	35
Sales	0	0	0
Issues	0	0	0
Settlements	(22)	(35)	0
Balance at end of period	6	5	35
Other investments
Assets
Balance at beginning of period	2	0
Total gains (losses) included in: net income	2	0
Total gains (losses) included in: OCI	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Purchases	0	3
Sales	(1)	(1)
Issues	0	0
Settlements	0	0
Balance at end of period	3	2	0
Other assets
Assets
Balance at beginning of period	65	0
Total gains (losses) included in: net income	38	65
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	103	65	0
Assets held for sale
Assets
Balance at beginning of period	$ 0	267	284
Total gains (losses) included in: net income		3	1
Total gains (losses) included in: OCI		(1)	(8)
Transfers into Level 3		17	52
Transfers out of Level 3		(13)	(42)
Purchases		4	24
Sales		(163)	(37)
Issues		0	0
Settlements		(6)	(7)
Balance at end of period		$ 0	$ 267