Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)									$ 143	$ 48	$ (330)
Net derivative gains (losses)									1,037	(1,070)	675
Net investment income									11,893	11,785	11,852
Income (loss) from continuing operations before provision for income tax									5,391	2,822	3,698
Provision for income tax expense (benefit)									(1,532)	(681)	(1,055)
Net income (loss)	979	1,303	749	825	581	242	646	673	3,856	2,142	2,683
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)									(605)	153	33
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Investment Gains (Losses), Net of Related Offsets [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)									(103)	(9)	(136)
Net derivative gains (losses)									(7)	(28)	(16)
Net investment income									40	53	56
Income (loss) from continuing operations before provision for income tax									(70)	16	(96)
Provision for income tax expense (benefit)									24	(6)	33
Net income (loss)									(46)	10	(63)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before provision for income tax									(682)	14	(2)
Provision for income tax expense (benefit)									239	(5)	1
Net income (loss)									(443)	9	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives | Interest rate forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)									(8)	1	0
Net investment income									2	2	2
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives | Foreign currency swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)									(725)	(15)	(7)
Net investment income									(2)	(3)	(5)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives | Credit forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income									1	1	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)									41	20	3
Net investment income									9	8	4
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined Benefit Plans Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of net actuarial gains (losses)									(180)	274	246
Amortization of prior service (costs) credit									0	(69)	(98)
Income (loss) from continuing operations before provision for income tax									(180)	205	148
Provision for income tax expense (benefit)									64	(71)	(51)
Net income (loss)									$ (116)	$ 134	$ 97