Consolidated Balance Sheet Parentheticals (Unaudited at March 31, 2020) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 65,630	$ 65,281
Fixed maturities, available for sale, allowance for expected credit losses	4	0
Equity securities, cost	372	376
Premiums receivable, allowance for expected credit losses	78	49
Reinsurance recoverables, allowance for estimated uncollectible reinsurance	149	92
Contractholder receivables, allowance for expected credit losses	$ 20	$ 20
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	252,900,000	255,500,000
Common stock, shares outstanding (in shares)	252,800,000	255,500,000
Treasury stock, at cost (in shares)	525,900,000	522,100,000