Related Party Transactions (Effects of Affiliated Reinsurance on Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Premiums:
Net premiums	$ 218	$ 228	$ 653	$ 607
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	826	811	2,447	2,381
Other revenues:
Other revenues	73	64	222	263
Interest credited to policyholder account balances:
Net interest credited to policyholder account balances	265	269	785	811
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Amortization Expense, [Abstract]
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Amortization	66	50	582	697
Other expenses:
Net other expenses	509	446	1,353	1,342
Affiliated Entity | Assumed
Premiums:
Reinsurance assumed	1	1	8	10
Universal life and investment-type product policy fees:
Reinsurance assumed	2	32	49	82
Other revenues:
Reinsurance assumed	0	0	1	28
Policyholder benefits and claims:
Reinsurance assumed	8	32	38	67
Affiliated Entity | Ceded
Premiums:
Reinsurance ceded	0	(106)	(201)	(423)
Universal life and investment-type product policy fees:
Reinsurance ceded	0	1	1	(17)
Other revenues:
Reinsurance ceded	0	0	18	39
Policyholder benefits and claims:
Reinsurance ceded	0	(89)	(177)	(317)
Affiliated Entity | Reinsurance
Premiums:
Net premiums	1	(105)	(193)	(413)
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	2	33	50	65
Other revenues:
Other revenues	0	0	19	67
Policyholder benefits and claims:
Net policyholder benefits and claims	$ 8	$ (57)	$ (139)	$ (250)