Segment Information (Reconciliation of Amortization of DAC and VOBA, Net of Interest from Segments to Consolidated Net Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	$ 1,111	$ 931	$ 1,026
Annuities [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	362	383	321
Retirement Plan Services [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	37	48	42
Life Insurance [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	655	447	614
Group Protection [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	$ 57	$ 53	$ 49