Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Preferred stock, par value	$ 1	$ 1
Preferred stock, authorized shares	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	283,433,401	283,433,401
Accumulated other comprehensive income (loss), taxes	$ 8	$ 8
Treasury stock, shares	229,505,963	204,000,108
Non Variable Interest Entity [Member]
Fixed-maturity securities held as available-for-sale, amortized cost	$ 2,184	$ 2,705
Short-term investments, amortized cost	346	423
Premiums receivable (net of allowance for credit losses)	4	0
Investments pledged as collateral, amortized cost	6	15
Medium-term notes, financial instruments carried at fair value	101	108
Variable Interest Entity Primary Beneficiary [Member]
Variable interest entity notes, financial instruments carried at fair value	343	403
Investments held-to-maturity, fair value	$ 575	$ 892