Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net investment gains (losses)	$ 374	$ 23
Net derivative gains (losses)	(630)	(1,978)
Net investment income	6,077	6,200
Other expenses	(4,138)	(4,321)
Other-than-temporary impairments on fixed maturity securities	(29)	(135)
Income (loss) from continuing operations before provision for income tax	1,247	(409)
Provision for income tax expense (benefit)	(252)	275
Amounts reclassified from AOCI, net of income tax	6
Net income (loss)	992	(120)
Unrealized Investment Gains (Losses) Net of Related Offsets [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI, net of income tax	159
Unrealized Gains (Losses) on Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI, net of income tax	(116)
Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI, net of income tax	(37)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	6
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]
Other net investment gains (losses)	290
Net investment income	21
Income (loss) from continuing operations before provision for income tax	280
Provision for income tax expense (benefit)	(121)
Net income (loss)	159
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Other-than-Temporary Impairment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-than-temporary impairments on fixed maturity securities	(31)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before provision for income tax	(181)
Provision for income tax expense (benefit)	65
Net income (loss)	(116)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives [Member] | Interest Rate Swaps [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	4
Net investment income	2
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives [Member] | Interest Rate Forwards [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	3
Net investment income	1
Other expenses	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives [Member] | Foreign Currency Swaps [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	(189)
Net investment income	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of net actuarial gains (losses)	(71)
Amortization of prior service (costs) credit	16
Income (loss) from continuing operations before provision for income tax	(55)
Provision for income tax expense (benefit)	18
Net income (loss)	$ (37)