Consolidated Balance Sheet Parentheticals - USD ($) shares in Millions, $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 68,830	$ 65,281
Fixed maturities, available for sale, allowance for expected credit losses	2	0
Equity securities, cost	387	376
Premiums receivable, allowance for expected credit losses	105	49
Reinsurance recoverables, allowance for estimated uncollectible reinsurance	146	92
Contractholder receivables, allowance for expected credit losses	$ 19	$ 20
Common stock, shares authorized (in shares)	1,750.0	1,750.0
Common stock, shares issued (in shares)	252.4	255.5
Common stock, shares outstanding (in shares)	252.4	255.5
Treasury stock, at cost (in shares)	527.3	522.1