Related Party Transactions (Effects of Affiliated Reinsurance on Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Premiums:
Net premiums	$ 220	$ 170
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	824	786
Other revenues:
Other revenues	79	62
Policyholder benefits and claims:
Net policyholder benefits and claims	710	858
Interest credited to policyholder account balances:
Net interest credited to policyholder account balances	260	267
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	281	(42)
Other expenses:
Net other expenses	397	436
Assumed
Premiums:
Reinsurance assumed	4	5
Universal life and investment-type product policy fees:
Reinsurance assumed	26	26
Other revenues:
Reinsurance assumed	1	0
Policyholder benefits and claims:
Reinsurance assumed	20	18
Ceded
Premiums:
Reinsurance ceded	(96)	(177)
Universal life and investment-type product policy fees:
Reinsurance ceded	(1)	(13)
Other revenues:
Reinsurance ceded	12	0
Policyholder benefits and claims:
Reinsurance ceded	(84)	(134)
Reinsurance
Premiums:
Net premiums	(92)	(172)
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	25	13
Other revenues:
Other revenues	13	0
Policyholder benefits and claims:
Net policyholder benefits and claims	$ (64)	$ (116)