Related Party Transactions (Effects of Affiliated Reinsurance on Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Reinsurance Disclosure [Line Items]
Change in market risk benefits	$ (293)	$ (610)	$ (86)	$ 1,185
Affiliated Entity | Assumed
Reinsurance Disclosure [Line Items]
Premiums	3	1	7	4
Universal life and investment-type product policy fees	0	(1)	0	(1)
Other revenues	0	0	1	1
Policyholder benefits and claims	3	4	11	11
Change in market risk benefits	9	15	(5)	(62)
Other expenses	$ (2)	$ (1)	$ (8)	$ 0