10-Q Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost, current	$ 30,139	$ 28,226	$ 25,641
Fixed maturities, allowance for credit loss, current	3	9	6
Fixed maturities, Amortized cost, Noncurrent	874	789	616
Fixed maturities, allowance for credit Loss, noncurrent	$ 0	$ 0	$ 0
Preferred stock, shares authorized	100,000,000	100,000,000	100,000,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	900,000,000	900,000,000	900,000,000
Common stock, shares issued	234,906,987	237,958,067	241,770,746
Common stock, shares outstanding	234,906,987	237,958,067	241,770,746