Consolidated Supplementary Insurance Information (Balance Sheet Items) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplementary Insurance Information, by Segment [Line Items]
DAC and VOBA	$ 5,274	$ 4,809	$ 4,890
Future Policy Benefits and Other Policy-Related Balances	35,068	33,443	31,799
Policyholder Account Balances	35,587	35,661	35,486
Unearned Premiums	18	18	14
Unearned Revenue	180	188	204
Annuities
Supplementary Insurance Information, by Segment [Line Items]
DAC and VOBA	4,521	3,510	3,548
Future Policy Benefits and Other Policy-Related Balances	7,251	6,395	5,205
Policyholder Account Balances	24,265	20,975	20,161
Unearned Premiums	0	0	0
Unearned Revenue	83	93	98
Life
Supplementary Insurance Information, by Segment [Line Items]
DAC and VOBA	504	680	680
Future Policy Benefits and Other Policy-Related Balances	3,871	4,438	3,968
Policyholder Account Balances	2,816	2,667	2,658
Unearned Premiums	12	12	9
Unearned Revenue	53	52	48
Run-off
Supplementary Insurance Information, by Segment [Line Items]
DAC and VOBA	112	510	601
Future Policy Benefits and Other Policy-Related Balances	16,522	15,446	15,860
Policyholder Account Balances	8,505	12,017	12,666
Unearned Premiums	0	0	0
Unearned Revenue	44	43	58
Corporate & Other
Supplementary Insurance Information, by Segment [Line Items]
DAC and VOBA	137	109	61
Future Policy Benefits and Other Policy-Related Balances	7,424	7,164	6,766
Policyholder Account Balances	1	2	1
Unearned Premiums	6	6	5
Unearned Revenue	$ 0	$ 0	$ 0