Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
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	283,625,689	283,625,689
Accumulated other comprehensive income (loss), taxes	$ 21	$ 8
Treasury stock, shares	203,157,759	193,803,976
Non Variable Interest Entity [Member]
Fixed-maturity securities held as available-for-sale, amortized cost	$ 2,734	$ 3,601
Investments pledged as collateral, amortized cost	14	46
Short-term investments, amortized cost	429	241
Medium-term notes, financial instruments carried at fair value	106	102
Variable Interest Entity Primary Beneficiary [Member]
Investments held-to-maturity, fair value	977	925
Variable interest entity notes, financial instruments carried at fair value	$ 472	$ 480