Condensed Consolidated Statements of Equity (Unaudited) (USD $) In Millions	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Notes receivable for the issuance of common stock [Member]	Parent [Member]	Noncontrolling interest [Member]
Balance at Dec. 31, 2010		$ 683	$ 2,200	$ 7,876	$ 326	$ (105)	$ (26)		$ 570
Cumulative effect adjustment from accounting change for deferred acquisition costs, net of tax (Accounting standards update 2010-26 [Member])				(72)					(7)
Stock-based compensation			(1)			4
Dividends paid to common stockholders				(27)
Net income (loss)	229			220					9
Other comprehensive income (loss)	87				89				(2)
Other			(1)						3
(Increase) decrease in notes receivable from the issuance of common stock							1
Balance at Mar. 31, 2011	11,740	683	2,198	7,997	415	(101)	(25)	11,167	573
Balance at Dec. 31, 2011		683	2,146	8,382	470	(102)	(22)
Cumulative effect adjustment from accounting change for deferred acquisition costs, net of tax (Accounting standards update 2010-26 [Member])			(5)	(74)	10
Stock-based compensation			(1)			2
Dividends paid to common stockholders				(41)
Net income (loss)	250			250
Other comprehensive income (loss)	284				284
Other
(Increase) decrease in notes receivable from the issuance of common stock							(1)
Balance at Mar. 31, 2012	$ 11,981	$ 683	$ 2,140	$ 8,517	$ 764	$ (100)	$ (23)	$ 11,981