Consolidated Supplementary Insurance Information (Income Statement Items) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Universal Life and Investment-Type Product Policy Fees	$ 3,617	$ 4,373	$ 4,345
Net Investment Income	2,712	2,615	2,669
Policyholder Benefits and Claims and Interest Credited to Policyholder Account Balances	3,941	3,733	3,826
Amortization of DAC and VOBA Charged to Other Expenses	(172)	595	990
Other Operating Expenses	1,738	1,722	1,764
Annuities
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Universal Life and Investment-Type Product Policy Fees	2,593	3,142	3,374
Net Investment Income	1,290	1,120	1,114
Policyholder Benefits and Claims and Interest Credited to Policyholder Account Balances	2,288	2,218	2,536
Amortization of DAC and VOBA Charged to Other Expenses	(825)	358	705
Other Operating Expenses	866	892	939
Life
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Universal Life and Investment-Type Product Policy Fees	333	431	282
Net Investment Income	275	277	281
Policyholder Benefits and Claims and Interest Credited to Policyholder Account Balances	330	355	291
Amortization of DAC and VOBA Charged to Other Expenses	239	128	172
Other Operating Expenses	300	288	278
Run-off [Member]
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Universal Life and Investment-Type Product Policy Fees	579	552	447
Net Investment Income	1,135	1,270	1,358
Policyholder Benefits and Claims and Interest Credited to Policyholder Account Balances	1,256	954	944
Amortization of DAC and VOBA Charged to Other Expenses	392	86	91
Other Operating Expenses	347	368	345
Corporate & Other
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Universal Life and Investment-Type Product Policy Fees	112	248	242
Net Investment Income	12	(52)	(84)
Policyholder Benefits and Claims and Interest Credited to Policyholder Account Balances	67	206	55
Amortization of DAC and VOBA Charged to Other Expenses	22	23	22
Other Operating Expenses	$ 225	$ 174	$ 202