General (Effects of Adoption of ASU 2018-12, Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022		Mar. 31, 2022		Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income taxes	$ 1,157	$ 1,251	[1]
Total assets	62,055	61,000	[1]
Claim and claim adjustment expenses	22,409	22,120	[1]
Future policy benefits	13,976	13,480	[1]	$ 16,002		$ 19,132
Total liabilities	53,388	52,452	[1]
Retained earnings	9,191	9,336	[1]
Accumulated other comprehensive loss	(3,308)	(3,598)	[1]
Total stockholders' equity	8,667	8,548	[1]	$ 9,698	[2]
Operating Segments | Life & Group
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Claim and claim adjustment expenses	704	695
Future policy benefits	$ 13,976	13,480
Prior to Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income taxes		1,178
Total assets		60,927
Claim and claim adjustment expenses		25,099
Future policy benefits		10,151				$ 13,318
Total liabilities		52,102
Retained earnings		9,572
Accumulated other comprehensive loss		(3,557)
Total stockholders' equity		8,825
Prior to Adoption | Operating Segments | Life & Group
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Claim and claim adjustment expenses		3,674
Future policy benefits		10,151
Effect of Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income taxes		73
Total assets		73
Claim and claim adjustment expenses		(2,979)
Future policy benefits		3,329
Total liabilities		350
Retained earnings		(236)
Accumulated other comprehensive loss		(41)
Total stockholders' equity		(277)
Effect of Adoption | Operating Segments | Life & Group
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Claim and claim adjustment expenses		(2,979)
Future policy benefits		$ 3,329

[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.

[2] 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.