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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Assets
Balance at beginning of period	$ 678	$ 851	$ 565	$ 832
Total gains (losses) included in: net income	54	9	92	27
Total gains (losses) included in: OCI	(3)	3	(4)	0
Transfers into Level 3	0	0	0	13
Transfers out of Level 3	(86)	(55)	(28)	(33)
Transfers to (from) held for sale		0		0
Purchases	91	36	118	91
Sales	(34)	(75)	(41)	(122)
Issues	0	0	0	0
Settlements	(24)	(42)	(26)	(81)
Balance at end of period	676	727	676	727
Liabilities
Balance at the beginning of the period	0	(463)	0	(516)
Total gains (losses) included in: net income	0	(24)	0	31
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	0
Sales	0	0	0	0
Issues	0	(8)	0	(16)
Settlements	0	5	0	11
Balance at the end of the period	0	(490)	0	(490)
Net investment income
Total Level 3 gains (losses) included in net income
Gain (loss) included in earnings	4	(5)	13	(6)
Net gains (losses) on investments and derivatives
Total Level 3 gains (losses) included in net income
Gain (loss) included in earnings	50	13	79	32
Liabilities held for sale
Liabilities
Balance at the beginning of the period		(463)		(516)
Total gains (losses) included in: net income	0	(24)	0	31
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		(8)		(16)
Settlements		5		11
Balance at the end of the period		(490)		(490)
Municipal
Assets
Balance at beginning of period	17	18	18	17
Total gains (losses) included in: net income	0	0	0	0
Total gains (losses) included in: OCI	1	0	1	1
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	1	0	1	3
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(1)	0	(2)	(3)
Balance at end of period	18	18	18	18
Corporate - public
Assets
Balance at beginning of period	49	43	20	67
Total gains (losses) included in: net income	0	0	0	0
Total gains (losses) included in: OCI	(1)	1	(3)	(2)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	(35)	(3)	0	0
Transfers to (from) held for sale		0		(6)
Purchases	71	0	71	14
Sales	(5)	(21)	(9)	(53)
Issues	0	0	0	0
Settlements	(2)	0	(2)	0
Balance at end of period	77	20	77	20
Corporate - privately placed
Assets
Balance at beginning of period	130	105	66	63
Total gains (losses) included in: net income	19	0	19	1
Total gains (losses) included in: OCI	(3)	2	(2)	0
Transfers into Level 3	0	0	0	10
Transfers out of Level 3	(51)	(27)	0	0
Transfers to (from) held for sale		1		14
Purchases	2	23	14	16
Sales	(24)	(20)	(24)	(20)
Issues	0	0	0	0
Settlements	0	0	0	0
Balance at end of period	73	84	73	84
ABS
Assets
Balance at beginning of period	19	102	40	79
Total gains (losses) included in: net income	0	0	1	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	(25)	(28)	(32)
Transfers to (from) held for sale		0		0
Purchases	0	0	7	34
Sales	0	(4)	0	(8)
Issues	0	0	0	0
Settlements	(1)	(40)	(2)	(40)
Balance at end of period	18	33	18	33
Fixed income securities
Assets
Balance at beginning of period	215	268	144	226
Total gains (losses) included in: net income	19	0	20	1
Total gains (losses) included in: OCI	(3)	3	(4)	(1)
Transfers into Level 3	0	0	0	10
Transfers out of Level 3	(86)	(55)	(28)	(32)
Transfers to (from) held for sale		1		8
Purchases	74	23	93	67
Sales	(29)	(45)	(33)	(81)
Issues	0	0	0	0
Settlements	(4)	(40)	(6)	(43)
Balance at end of period	186	155	186	155
Equity securities
Assets
Balance at beginning of period	373	410	349	304
Total gains (losses) included in: net income	4	8	29	25
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		8		100
Purchases	0	6	2	10
Sales	(5)	(27)	(8)	(34)
Issues	0	0	0	0
Settlements	0	0	0	0
Balance at end of period	372	405	372	405
Short-term investments
Assets
Balance at beginning of period	11	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	17	0	23	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(20)	0	(20)	(35)
Balance at end of period	8	0	8	0
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	0	0	0
Issues	0	0	0	0
Settlements	0	0	0	0
Balance at end of period	2	3	2	3
Other assets
Assets
Balance at beginning of period	77		65
Total gains (losses) included in: net income	31		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	0		0
Issues	0		0
Settlements	0		0
Balance at end of period	$ 108		$ 108
Assets held for sale
Assets
Balance at beginning of period		170		267
Total gains (losses) included in: net income		1		1
Total gains (losses) included in: OCI		0		1
Transfers into Level 3		0		3
Transfers out of Level 3		0		(1)
Transfers to (from) held for sale		(9)		(108)
Purchases		7		11
Sales		(3)		(7)
Issues		0		0
Settlements		(2)		(3)
Balance at end of period		$ 164		$ 164