Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	$ 1,658		$ 1,658			$ 1,504
Accumulated other comprehensive income, net of tax, end of period	1,658		1,658			1,504
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	2,687	1,987	2,335	1,875
Other comprehensive income before reclassification, before tax	(55)	82	332	246
Reclassification adjustment, before tax	(65)	(20)	(100)	(72)
Effect on other comprehensive income, before tax	(120)	62	232	174
Accumulated other comprehensive income, before tax, end of period	2,567	2,049	2,567	2,049
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	931	686	808	647
Other comprehensive income before reclassification, tax	(20)	29	115	85
Reclassification adjustment, tax	(22)	(7)	(34)	(24)
Effect on other comprehensive income, tax	(42)	22	81	61
Accumulated other comprehensive income, tax, end of period	889	708	889	708
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1,678	1,341	1,678	1,341	1,756	1,527	1,301	1,228
Other comprehensive income before reclassification, net of tax	(35)	53	217	161
Reclassification adjustment, net of tax	(43)	(13)	(66)	(48)
Effect on other comprehensive income, net of tax	(78)	40	151	113
Accumulated other comprehensive income, net of tax, end of period	1,678	1,341	1,678	1,341	1,756	1,527	1,301	1,228
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(19)	(96)	(18)	(101)
Other comprehensive income before reclassification, before tax	0	0	0	0
Reclassification adjustment, before tax	1	2	0	7
Effect on other comprehensive income, before tax	1	2	0	7
Accumulated other comprehensive income, before tax, end of period	(18)	(94)	(18)	(94)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(6)	(33)	(6)	(35)
Other comprehensive income before reclassification, tax	0	0	0	0
Reclassification adjustment, tax	0	1	0	3
Effect on other comprehensive income, tax	0	1	0	3
Accumulated other comprehensive income, tax, end of period	(6)	(32)	(6)	(32)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(12)	(62)	(12)	(62)	(13)	(12)	(63)	(66)
Other comprehensive income before reclassification, net of tax	0	0	0	0
Reclassification adjustment, net of tax	1	1	0	4
Effect on other comprehensive income, net of tax	1	1	0	4
Accumulated other comprehensive income, net of tax, end of period	(12)	(62)	(12)	(62)	(13)	(12)	(63)	(66)
Accumulated Net Unrealized Gain (Loss) on Deferred Costs, Reserves And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(16)	(26)	(16)	(50)
Other comprehensive income before reclassification, before tax	5	9	6	36
Reclassification adjustment, before tax	0	(2)	(1)	(5)
Effect on other comprehensive income, before tax	5	7	5	31
Accumulated other comprehensive income, before tax, end of period	(11)	(19)	(11)	(19)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(5)	(9)	(5)	(17)
Other comprehensive income before reclassification, tax	2	2	3	12
Reclassification adjustment, tax	0	0	(1)	(2)
Effect on other comprehensive income, tax	2	2	2	10
Accumulated other comprehensive income, tax, end of period	(3)	(7)	(3)	(7)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(8)	(12)	(8)	(12)	(11)	(11)	(17)	(33)
Other comprehensive income before reclassification, net of tax	3	7	3	24
Reclassification adjustment, net of tax	0	(2)	0	(3)
Effect on other comprehensive income, net of tax	3	5	3	21
Accumulated other comprehensive income, net of tax, end of period	(8)	(12)	(8)	(12)	(11)	(11)	(17)	(33)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	2,652	1,865	2,301	1,724
Change in unrealized gains, net, on investments available for sale, before tax	(120)	62	232	174
Change in pension obligations, before tax	1	2	0	7
Change in life deferred acquisition costs, life policy reserves and other, before tax	5	7	5	31
Effect on other comprehensive income, before tax	(114)	71	237	212
Accumulated other comprehensive income, before tax, end of period	2,538	1,936	2,538	1,936
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	920	644	797	595
Change in unrealized gains, net, on investments available for sale, tax	(42)	22	81	61
Change in pension obligations, tax	0	1	0	3
Change in life deferred acquisition costs, life policy reserves and other, tax	2	2	2	10
Effect on other comprehensive income, tax	(40)	25	83	74
Accumulated other comprehensive income, tax, end of period	880	669	880	669
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1,658	1,267	1,658	1,267	1,732	1,504	1,221	1,129
Change in unrealized gains, net, on investments available for sale, net of tax	(78)	40	151	113
Change in pension obligations, net of tax	1	1	0	4
Change in life deferred acquisition costs, life policy reserves and other, net of tax	3	5	3	21
Effect on other comprehensive income, net of tax	(74)	46	154	138
Accumulated other comprehensive income, net of tax, end of period	$ 1,658	$ 1,267	$ 1,658	$ 1,267	$ 1,732	$ 1,504	$ 1,221	$ 1,129