Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Insurance premiums	$ 2,988	$ 2,687	$ 2,462
Fee income	4,673	4,069	3,736
Net investment income	4,859	4,754	4,698
Realized gain (loss):
Total other-than-temporary impairment losses on securities	(26)	(80)	(259)
Portion of loss recognized in other comprehensive income	10	10	106
Net other-than-temporary impairment losses on securities recognized in earnings	(16)	(70)	(153)
Realized gain (loss), excluding other-than-temporary impairment losses on securities	16	(65)	227
Total realized gain (loss)		(135)	74
Amortization of deferred gain on business sold through reinsurance	74	74	74
Other revenues	960	520	491
Total revenues	13,554	11,969	11,535
Expenses
Interest credited	2,532	2,510	2,470
Benefits	4,679	3,862	3,541
Commissions and other expenses	4,079	3,701	3,683
Interest and debt expense	267	265	273
Impairment of intangibles
Total expenses	11,557	10,338	9,967
Income (loss) from continuing operations before taxes	1,997	1,631	1,568
Federal income tax expense (benefit)	483	387	282
Income (loss) from continuing operations	1,514	1,244	1,286
Income (loss) from discontinued operations, net of federal income taxes	1		27
Net income (loss)	1,515	1,244	1,313
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized gain (loss) on available-for-sale securities	1,688	(2,457)	1,119
Unrealized other-than-temporary impairment on available-for-sale securities	20	29	2
Unrealized gain (loss) on derivative instruments	(117)	93	44
Foreign currency translation adjustment	2	(1)	(5)
Funded status of employee benefit plans	(60)	91	(32)
Total other comprehensive income (loss), net of tax	1,533	(2,245)	1,128
Comprehensive income (loss)	$ 3,048	$ (1,001)	$ 2,441
Earnings (Loss) Per Common Share - Basic
Income (loss) from continuing operations (in dollars per share)	$ 5.81	$ 4.68	$ 4.58
Income (loss) from discontinued operations (in dollars per share)			$ 0.10
Net income (loss) (in dollars per share)	$ 5.81	$ 4.68	$ 4.68
Earnings (Loss) Per Common Share - Diluted
Income (loss) from continuing operations (in dollars per share)	$ 5.67	$ 4.52	$ 4.47
Income (loss) from discontinued operations (in dollars per share)			$ 0.09
Net income (loss) (in dollars per share)	$ 5.67	$ 4.52	$ 4.56