Reinsurance (Effects of Affiliated Reinsurance on Statements of Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Premiums:
Reinsurance assumed	$ 79	$ 297	$ 94
Reinsurance ceded	(1,275)	(1,145)	(1,168)
Net premiums	921	1,433	1,152
Universal life and investment-type product policy fees:
Reinsurance assumed	129	142	398
Reinsurance ceded	(909)	(809)	(815)
Net universal life and investment-type product policy fees	2,696	2,940	3,193
Other revenues:
Reinsurance assumed	87	0	28
Reinsurance ceded	415	246	252
Net other revenues	761	504	539
Policyholder benefits and claims:
Reinsurance assumed	128	305	263
Reinsurance ceded	(3,053)	(2,416)	(2,296)
Net policyholder benefits and claims	2,984	2,696	2,764
Interest credited to policyholder account balances:
Reinsurance assumed	75	78	76
Reinsurance ceded	(145)	(145)	(139)
Net interest credited to policyholder account balances	957	1,037	1,062
Reinsurance assumed	148	8	100
Reinsurance ceded	(206)	(43)	(68)
Direct amortization of deferred policy acquisition costs and value of business acquired	(172)	595	990
Other expenses:
Reinsurance assumed	35	47	6
Reinsurance ceded	221	163	192
Net other expenses	1,738	1,722	1,764
Affiliated Entity [Member]
Other expenses:
Net other expenses	820	1,000	985
Affiliated Entity [Member] | Assumed
Premiums:
Reinsurance assumed	34	227	55
Universal life and investment-type product policy fees:
Reinsurance assumed	129	142	291
Other revenues:
Reinsurance assumed	56	0	28
Policyholder benefits and claims:
Reinsurance assumed	91	255	229
Interest credited to policyholder account balances:
Reinsurance assumed	75	78	76
Reinsurance assumed	49	24	90
Other expenses:
Reinsurance assumed	19	41	2
Affiliated Entity [Member] | Ceded
Premiums:
Reinsurance ceded	(928)	(783)	(830)
Universal life and investment-type product policy fees:
Reinsurance ceded	(359)	(299)	(361)
Other revenues:
Reinsurance ceded	414	246	252
Policyholder benefits and claims:
Reinsurance ceded	(1,304)	(925)	(942)
Interest credited to policyholder account balances:
Reinsurance ceded	(145)	(145)	(139)
Reinsurance ceded	(189)	(40)	(63)
Other expenses:
Reinsurance ceded	242	186	219
Affiliated Entity [Member] | Reinsurance [Member]
Premiums:
Net premiums	(894)	(556)	(775)
Universal life and investment-type product policy fees:
Net universal life and investment-type product policy fees	(230)	(157)	(70)
Other revenues:
Net other revenues	470	246	280
Policyholder benefits and claims:
Net policyholder benefits and claims	(1,213)	(670)	(713)
Interest credited to policyholder account balances:
Net interest credited to policyholder account balances	(70)	(67)	(63)
Direct amortization of deferred policy acquisition costs and value of business acquired	(140)	(16)	27
Other expenses:
Net other expenses	$ 261	$ 227	$ 221