Segment Information (Reconciliation of Federal Income Tax Expense (Benefit) 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
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	$ 387	$ 282	$ 274
Parent Company [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	(73)	(85)	(68)
Annuities [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	177	121	104
Retirement Plan Services [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	49	38	63
Life Insurance [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	268	264	276
Group Protection [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	38	39	52
Other Operations [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	(71)	(177)	(77)
Excluded realized gain (loss) [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	(95)	(14)	(136)
Gain (loss) on early extinguishment of debt [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)		(2)	(3)
Reserve changes (net of related amortization) on business sold through reinsurance [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	1	1	1
Impairment of intangibles [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)		(2)
Benefit ratio unlocking [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)	$ 20	$ 14	$ (6)