Future Policy Benefit Reserves - Summary of Balances and Changes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Present value of future net premiums
Balance, January 1	$ 3,993	$ 4,735
Effect of changes in discount rate	(154)	(525)	$ (74)		$ (880)
Balance, January 1, at original locked in discount rate	3,919	3,855
Effect of changes in cash flow assumptions			0		0
Expect of actual variances from expected experience			(49)		(18)
Adjusted balance, January 1			3,870		3,837
Interest accrual	52	53
Net premiums: earned during period	(111)	(112)
Balance, end of period at original locked in discount rate	3,811	3,778
Effect of changes in discount rate	154	525	74		880
Balance, March 31	3,965	4,303
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, January 1	17,472	22,745
Effect of changes in discount rate	(704)	(3,517)	(125)		(5,942)
Balance, January 1, at original locked in discount rate	17,347	16,803
Effect of change in cash flow assumptions			0		0
Effect of actual variances from expected experience			(50)		(23)
Adjusted balance, January 1			17,297		16,780
Interest accrual	242	241
Benefit & expense payments	(302)	(233)
Balance, end of period at original locked in discount rate	17,237	16,788
Effect of changes in discount rate	704	3,517	125		$ 5,942
Balance, March 31	17,941	20,305
Net LFPB	$ 13,976	$ 16,002	$ 13,480	[1]		$ 19,132

[1] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance. See Note A to the Condensed Consolidated Financial Statements for additional information.