Condensed Consolidated Balance Sheets - (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Fixed maturities securities at amortized cost	$ 39,826	$ 38,953
Marketable securities fixed maturities allowance for credit loss	45	40
Equity securities at cost	955	941
Mortgage loans on real estate commercial and consumer allowance for credit loss	26	26
Allowance for uncollectible reinsurance	22	21
Allowance for uncollectible insurance receivables	34	33
Accumulated depreciation on property and equipment	252	231
Due to related parties	$ 74	$ 89
Common stock, par value (in usd per share)	$ 2.50	$ 2.50
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	273,040,243	273,040,243
Common stock, shares outstanding (in shares)	271,349,927	271,391,603
Treasury stock, shares (in shares)	1,690,316	1,648,640