Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	$ (527)		$ (614)
Accumulated other comprehensive income, net of tax, end of period	(527)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Other comprehensive income before reclassification, before tax	163	$ (743)
Reclassification adjustment, before tax	0	(3)
Effect on other comprehensive income, before tax	163	(746)
Accumulated other comprehensive income, before tax, end of period	(684)	46
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Other comprehensive income before reclassification, tax	35	(157)
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	35	(157)
Accumulated other comprehensive income, tax, end of period	(147)	8
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(537)	38
Other comprehensive income before reclassification, net of tax	128	(586)
Reclassification adjustment, net of tax	0	(3)
Effect on other comprehensive income, net of tax	128	(589)
Accumulated other comprehensive income, net of tax, end of period	(537)	38
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	36	27
Other comprehensive income before reclassification, before tax	(5)	0
Reclassification adjustment, before tax	(1)	0
Effect on other comprehensive income, before tax	(6)	0
Accumulated other comprehensive income, before tax, end of period	30	27
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	9	7
Other comprehensive income before reclassification, tax	(1)	0
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	(1)	0
Accumulated other comprehensive income, tax, end of period	8	7
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	22	20	27	$ 20
Other comprehensive income before reclassification, net of tax	(4)	0
Reclassification adjustment, net of tax	(1)	0
Effect on other comprehensive income, net of tax	(5)	0
Accumulated other comprehensive income, net of tax, end of period	22	20
Accumulated Net Unrealized Gain (Loss) on Life Policy Reserves, Reinsurance Recoverable And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	29	(444)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	5	(93)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			24	(351)
Accumulated Net Unrealized Gain (Loss) on Life Policy Reserves, Reinsurance Recoverable And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Other comprehensive income before reclassification, before tax	(45)	196
Reclassification adjustment, before tax	0	0
Effect on other comprehensive income, before tax	(45)	196
Accumulated other comprehensive income, before tax, end of period	(16)	(248)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Other comprehensive income before reclassification, tax	(9)	41
Reclassification adjustment, tax	0	0
Effect on other comprehensive income, tax	(9)	41
Accumulated other comprehensive income, tax, end of period	(4)	(52)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(12)	(196)
Other comprehensive income before reclassification, net of tax	(36)	155
Reclassification adjustment, net of tax	0	0
Effect on other comprehensive income, net of tax	(36)	155
Accumulated other comprehensive income, net of tax, end of period	(12)	(196)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(782)	375
Change in unrealized gains, net, on investments available for sale, before tax	163	(746)
Change in pension obligations, before tax	(6)	0
Change in Life Policy Reserves, Reinsurance Recoverable and Other	(45)	196
Effect on other comprehensive income, before tax	112	(550)
Accumulated other comprehensive income, before tax, end of period	(670)	(175)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(168)	79
Change in unrealized gains, net, on investments available for sale, tax	35	(157)
Change in pension obligations, tax	(1)	0
Change in Life Policy Reserves, Reinsurance Recoverable and Other, Tax	(9)	41
Effect on other comprehensive income, tax	25	(116)
Accumulated other comprehensive income, tax, end of period	(143)	(37)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(527)	(138)	(614)	296
Change in unrealized gains, net, on investments available for sale, net of tax	128	(589)
Change in pension obligations, net of tax	(5)	0
Change in Life Policy Reserves, Reinsurance Recoverable and Other, Net of Tax	(36)	155
Effect on other comprehensive income, net of tax	87	(434)
Accumulated other comprehensive income, net of tax, end of period	(527)	(138)
As originally reported | Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(847)	792
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(182)	165
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			(665)	627
As originally reported | Accumulated Net Unrealized Gain (Loss) on Life Policy Reserves, Reinsurance Recoverable And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	29	1
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	5	0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			24	1
As originally reported | Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(782)	820
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(168)	172
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			(614)	648
As adjusted | Accumulated Net Unrealized Gain (Loss) on Life Policy Reserves, Reinsurance Recoverable And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	0	(445)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	0	(93)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			0	(352)
As adjusted | Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	0	(445)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	$ 0	$ (93)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period			$ 0	$ (352)