Basis of Presentation - Adoption on Consolidated Condensed Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	$ 3,994	$ 4,014
Total assets	76,560	75,567
Claim and claim adjustment expense	22,409	22,120	$ 21,415	$ 21,269
Future policy benefits	13,976	13,480	16,002		$ 19,132
Total liabilities	61,246	60,366
Retained earnings	15,293	14,931
Accumulated other comprehensive loss	(3,062)	(3,320)
Noncontrolling interests	863	852
Total equity	$ 15,314	15,201	$ 16,576	17,471
As Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets		3,941
Total assets		75,494
Claim and claim adjustment expense		25,099
Future policy benefits		10,151			$ 13,318
Total liabilities		60,016
Retained earnings		15,144
Accumulated other comprehensive loss		(3,284)
Noncontrolling interests		880
Total equity		15,478		19,175
Effect of Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets		73
Total assets		73
Claim and claim adjustment expense		(2,979)
Future policy benefits		3,329
Total liabilities		350
Retained earnings		(213)
Accumulated other comprehensive loss		(36)
Noncontrolling interests		(28)
Total equity		$ (277)		$ (1,704)