Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	$ 59		$ 648
Accumulated other comprehensive income, net of tax, end of period	59
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Other comprehensive income before reclassification, before tax	(743)	$ (193)
Reclassification adjustment, before tax	(3)	(3)
Effect on other comprehensive income, before tax	(746)	(196)
Accumulated other comprehensive income, before tax, end of period	46	830
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Other comprehensive income before reclassification, tax	(157)	(41)
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	(157)	(41)
Accumulated other comprehensive income, tax, end of period	8	174
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	38	656
Other comprehensive income before reclassification, net of tax	(586)	(152)
Reclassification adjustment, net of tax	(3)	(3)
Effect on other comprehensive income, net of tax	(589)	(155)
Accumulated other comprehensive income, net of tax, end of period	38	656
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	27	(41)
Other comprehensive income before reclassification, before tax	0	2
Reclassification adjustment, before tax	0	2
Effect on other comprehensive income, before tax	0	4
Accumulated other comprehensive income, before tax, end of period	27	(37)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	7	(7)
Other comprehensive income before reclassification, tax	0	1
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	0	1
Accumulated other comprehensive income, tax, end of period	7	(6)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	20	(31)	20	$ (34)
Other comprehensive income before reclassification, net of tax	0	1
Reclassification adjustment, net of tax	0	2
Effect on other comprehensive income, net of tax	0	3
Accumulated other comprehensive income, net of tax, end of period	20	(31)
Accumulated Net Unrealized Gain (Loss) on Deferred Costs, Reserves And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	1	(10)
Other comprehensive income before reclassification, before tax	0	10
Reclassification adjustment, before tax	0	0
Effect on other comprehensive income, before tax	0	10
Accumulated other comprehensive income, before tax, end of period	1	0
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	0	(2)
Other comprehensive income before reclassification, tax	0	2
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	0	2
Accumulated other comprehensive income, tax, end of period	0	0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1	0	1	(8)
Other comprehensive income before reclassification, net of tax	0	8
Reclassification adjustment, net of tax	0	0
Effect on other comprehensive income, net of tax	0	8
Accumulated other comprehensive income, net of tax, end of period	1	0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Change in unrealized gains, net, on investments available for sale, before tax	(746)	(196)
Change in pension obligations, before tax	0	4
Change in life deferred acquisition costs, life policy reserves and other, before tax	0	10
Effect on other comprehensive income, before tax	(746)	(182)
Accumulated other comprehensive income, before tax, end of period	74	793
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Change in unrealized gains, net, on investments available for sale, tax	(157)	(41)
Change in pension obligations, tax	0	1
Change in life deferred acquisition costs, life policy reserves and other, tax	0	2
Effect on other comprehensive income, tax	(157)	(38)
Accumulated other comprehensive income, tax, end of period	15	168
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	59	625
Change in unrealized gains, net, on investments available for sale, net of tax	(589)	(155)
Change in pension obligations, net of tax	0	3
Change in life deferred acquisition costs, life policy reserves and other, net of tax	0	8
Effect on other comprehensive income, net of tax	(589)	(144)
Accumulated other comprehensive income, net of tax, end of period	59	625
Previously Reported | Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	792	1,026
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	165	215
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			627	811
Previously Reported | Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	820	975
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	$ 172	$ 206
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			$ 648	$ 769