Accumulated Other Comprehensive Income Level 4 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 8,789	$ 9,492	$ 8,789	$ 9,492		$ 9,291		$ 8,239
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(467)	233	(344)	563
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(18)	27	(28)	9
Other Comprehensive Income (Loss), Net of Tax	(485)	260	(372)	572
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	15	653	12	554
Income before income taxes	241	570	426	614
Income Tax Expense (Benefit)	11	171	51	158
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	790	1,066	790	1,066	$ 1,257	1,154	$ 810	495
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(457)	227	(342)	544
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(10)	29	(22)	27
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(467)	256	(364)	571
Gain (Loss) on Investments, Excluding Other than Temporary Impairments		(44)	34	(41)
Income before income taxes				(41)
Income Tax Expense (Benefit)	6	(15)	12	(14)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	62	80	62	80	80	70	77	79
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(10)	5	(2)	19
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(8)	(2)	(6)	(18)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(18)	3	(8)	1
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(3)	0	(3)	0	(3)	(3)	(1)	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	1	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	1	0	0
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	849	1,146	849	1,146	$ 1,334	$ 1,221	$ 886	$ 574
Other Comprehensive Income (Loss), Net of Tax				572
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	18	(27)	28	(9)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	10	(29)	22	(27)
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	16	(44)	34	(41)
Income before income taxes	16	(44)	34
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income Tax Expense (Benefit)	4	1	3	9
Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	12	3	9	27
Cash Flow Hedging [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	8	2	6	18
Income before income taxes	12	3	9	27
Interest Rate Swap [Member] | Interest Income [Member] | Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	9		17
Interest Rate Swap [Member] | Interest Income [Member] | Cash Flow Hedging [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	9	3	17	26
Interest Rate Swap [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Cash Flow Hedging [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net			(1)
Interest Rate Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0		(1)
Interest Rate Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Cash Flow Hedging [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0		1
Currency Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	3		(7)
Currency Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Cash Flow Hedging [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 3	$ 0	$ (7)	$ 0