Acquisitions and Dispositions (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred income tax expense (benefit) related to unrealized investment gains (losses)	$ 2,028
Investments in Foreign Subsidiaries and Foreign Corporate Joint Ventures that are Essentially Permanent in Duration [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Balance, beginning of period	720
Income tax expense (benefit)	(1)
Deferred income tax expense (benefit) related to unrealized investment gains (losses)	295
Offsetting reduction in gross deferred tax asset related to the branch transfer to subsidiary	(896)
Balance, end of period	118
Investments in Foreign Subsidiaries and Foreign Corporate Joint Ventures that are Essentially Permanent in Duration [Member] | Asia [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Balance, beginning of period	566
Income tax expense (benefit)	10
Deferred income tax expense (benefit) related to unrealized investment gains (losses)	320
Offsetting reduction in gross deferred tax asset related to the branch transfer to subsidiary	(896)
Balance, end of period	0
Investments in Foreign Subsidiaries and Foreign Corporate Joint Ventures that are Essentially Permanent in Duration [Member] | Europe, the Middle East and Africa [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Balance, beginning of period	154
Income tax expense (benefit)	(11)
Deferred income tax expense (benefit) related to unrealized investment gains (losses)	(25)
Offsetting reduction in gross deferred tax asset related to the branch transfer to subsidiary	0
Balance, end of period	$ 118