Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Total revenues	$ 4,222	$ 4,781	$ 5,088	$ 4,674	$ 5,229	$ 5,238	$ 4,862	$ 4,533					$ 18,766	$ 19,862	$ 17,439
Total expenses	4,238	7,929	4,831	4,597	4,375	4,872	4,086	4,279					21,596	17,613	17,016
Net income (loss)	$ 21	$ (2,583)	$ 228	$ 92	$ 708	$ 316	$ 645	$ 219	$ 319	$ 864	$ (2,264)	$ 1,180	$ (2,241)	$ 1,887	$ 499
Earnings (loss) per common share - basic:
Net income (loss) (in dollars per share)	$ 0.12	$ (15.22)	$ 1.34	$ 0.53	$ 3.92	$ 1.69	$ 3.40	$ 1.14					$ (13.11)	$ 10.07	$ 2.58
Earnings (loss) per common share - diluted:
Net income (loss) (in dollars per share)	$ 0.09	$ (15.23)	$ 1.28	$ 0.52	$ 3.86	$ 1.67	$ 3.36	$ 1.13					$ (13.19)	$ 9.98	$ 2.56
Parent Company [Member]
Total revenues													$ 959	$ 2,175	$ 971
Total expenses													356	342	345
Net income (loss)													$ (2,241)	$ 1,887	$ 499