Adoption of ASU 2018-12 (Cumulative Effect Adjustments to Components of Stockholders’ Equity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Stockholders' equity		$ 7,318		$ 8,604	$ 6,884
Retained Earnings (Deficit) [Member]
Stockholders' equity		(520)	$ (730)	1,414	1,080	$ 3,647	$ 3,734
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' equity		$ (5,110)	$ (1,804)	$ (5,713)	(6,310)	$ (1,768)	10,250
Accounting Standards Update 2018-12 [Member]
Stockholders' equity					6,884
Accounting Standards Update 2018-12 [Member] | Retained Earnings (Deficit) [Member]
Stockholders' equity					1,080		3,734
Accounting Standards Update 2018-12 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' equity					$ (6,310)		$ 10,250
Accounting Standards Update 2018-12 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
DAC, VOBA, DSI and DFEL	$ 2,271
Additional liabilities for other insurance benefits	1,197
Liability for future policy benefits and other	(1,641)
MRBs	1,175
Total	3,002
Accounting Standards Update 2018-12 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings (Deficit) [Member]
Liability for future policy benefits and other	(121)
MRBs	(1,699)
Total	(1,820)
Accounting Standards Update 2018-12 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
DAC, VOBA, DSI and DFEL	2,271
Additional liabilities for other insurance benefits	1,197
Liability for future policy benefits and other	(1,520)
MRBs	2,874
Total	$ 4,822