Related Party Transactions (Effects of Affiliated Reinsurance on Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Premiums:
Net premiums	$ 215	$ 209	$ 435	$ 379
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	797	784	1,621	1,570
Other revenues:
Other revenues	70	137	149	199
Interest credited to policyholder account balances:
Net interest credited to policyholder account balances	260	275	520	542
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	235	689	516	647
Other expenses:
Net other expenses	447	460	844	896
Assumed
Premiums:
Reinsurance assumed	3	4
Universal life and investment-type product policy fees:
Reinsurance assumed	21	24
Other revenues:
Reinsurance assumed	0	28
Policyholder benefits and claims:
Reinsurance assumed	10	17
Ceded
Premiums:
Reinsurance ceded	(105)	(140)
Universal life and investment-type product policy fees:
Reinsurance ceded	2	(5)
Other revenues:
Reinsurance ceded	6	39
Policyholder benefits and claims:
Reinsurance ceded	(93)	(94)
Reinsurance
Premiums:
Net premiums	(102)	(136)
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	23	19
Other revenues:
Other revenues	6	67
Policyholder benefits and claims:
Net policyholder benefits and claims	$ (83)	$ (77)
Affiliated Entity | Assumed
Premiums:
Reinsurance assumed			7	9
Universal life and investment-type product policy fees:
Reinsurance assumed			47	50
Other revenues:
Reinsurance assumed			1	28
Policyholder benefits and claims:
Reinsurance assumed			30	35
Affiliated Entity | Ceded
Premiums:
Reinsurance ceded			(201)	(317)
Universal life and investment-type product policy fees:
Reinsurance ceded			1	(18)
Other revenues:
Reinsurance ceded			18	39
Policyholder benefits and claims:
Reinsurance ceded			(177)	(228)
Affiliated Entity | Reinsurance
Premiums:
Net premiums			(194)	(308)
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees			48	32
Other revenues:
Other revenues			19	67
Policyholder benefits and claims:
Net policyholder benefits and claims			$ (147)	$ (193)