Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net investment gains (losses)	$ 149	$ 27	$ 523	$ 50
Net derivative gains (losses)	(1,690)	2,092	(2,320)	114
Net investment income	5,282	4,719	11,359	10,919
Other expenses	(4,025)	(4,775)	(8,163)	(9,096)
Other-than-temporary impairments on fixed maturity securities	(35)	(118)	(64)	(253)
Income (loss) from continuing operations before provision for income tax	561	3,338	1,808	2,929
Provision for income tax expense (benefit)	(53)	(1,038)	(305)	(763)
Amounts reclassified from AOCI, net of income tax	69		75
Net income (loss)	510	2,303	1,502	2,183
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	147		306
Unrealized Gains (Losses) on Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI, net of income tax	(44)		(160)
Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI, net of income tax	(34)		(71)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	69		75
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)	171		461
Net investment income	22		43
Income (loss) from continuing operations before provision for income tax	189		469
Provision for income tax expense (benefit)	(42)		(163)
Net income (loss)	147		306
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	(4)		(35)
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	(53)		(234)
Provision for income tax expense (benefit)	9		74
Net income (loss)	(44)		(160)
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)	10		14
Net investment income	2		4
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		6
Net investment income	0		1
Other expenses	0		(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)	(68)		(257)
Net investment income	(1)		(2)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Derivatives [Member] | Credit forwards [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income	1		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)	(70)		(141)
Amortization of prior service (costs) credit	18		34
Income (loss) from continuing operations before provision for income tax	(52)		(107)
Provision for income tax expense (benefit)	18		36
Net income (loss)	$ (34)		$ (71)