Supplementary Data on Cash Flows (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 314	$ 267	$ 177	$ 290	$ 119	$ 184	$ (38)	$ 354	$ 1,048	$ 619	$ 268
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation									21	17	4
Amortization of deferred policy acquisition costs									778	715	680
Deferred income tax expense (benefit)									198	118	(105)
Realized (gains) losses and impairments on investments									(758)	(418)	6
Equity in earnings of limited partnerships									(161)	(131)	(149)
Net amortization of bond premium									36	28	26
Increase in deferred compensation									8	2	4
Limited partnership distributions									176	164	166
(Increase) decrease in receivables, reinsurance recoverables, and reserve credits									(112)	(166)	91
Decrease (increase) in prepaid expenses									24	63	(56)
Increase in deferred policy acquisition costs									(816)	(743)	(701)
Increase (decrease) in accounts payable and accrued expenses									18	(28)	83
Increase in accrued commissions and agent bonuses									28	20	4
Increase (decrease) in loss reserves									148	99	(85)
Increase in future life policy benefits and claims reserves									34	31	28
Increase in unearned premiums									233	187	96
Net cash provided by operating activities									$ 903	$ 577	$ 360