Segment Information (Reconciliation of Net Investment Income from Segments to Consolidated Net Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Abstract]
Total net investment income	$ 4,754	$ 4,698	$ 4,652
Parent Company [Member]
Net Investment Income [Abstract]
Total net investment income		1	2
Annuities [Member]
Net Investment Income [Abstract]
Total net investment income	1,044	1,082	1,106
Retirement Plan Services [Member]
Net Investment Income [Abstract]
Total net investment income	827	799	792
Life Insurance [Member]
Net Investment Income [Abstract]
Total net investment income	2,452	2,396	2,294
Group Protection [Member]
Net Investment Income [Abstract]
Total net investment income	165	162	152
Other Operations [Member]
Net Investment Income [Abstract]
Total net investment income	$ 266	$ 259	$ 308