Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
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	283,186,115	283,186,115
Accumulated other comprehensive income (loss), taxes	$ 7	$ 8
Treasury stock, shares	228,221,641	228,333,444
Non Variable Interest Entity [Member]
Fixed-maturity securities held as available-for-sale, amortized cost	$ 2,141	$ 2,044
Short-term investments, amortized cost	367	353
Premiums receivable (net of allowance for credit losses)	0	0
Medium-term notes, financial instruments carried at fair value	42	41
Variable Interest Entity Primary Beneficiary [Member]
Variable interest entity debt (includes financial instruments carried at fair value)	$ 154	$ 172