Consolidated Statement of Changes in Equity (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	Total USD ($)	Common Shares	Common Stock and Capital Surplus USD ($)	Retained Earnings Appro. USD ($)	Retained Earnings Unappro. USD ($)	Accum. Other Comprehensive Inc. (Loss) USD ($)	Total USD ($)	Noncontrolling Interests USD ($)
Beginning Balance at Dec. 31, 2009
Balance at December 31, 2010	$ 4,620		$ 1,271	$ 197	$ 2,523	$ 479	$ 4,470	$ 150
Balance, shares at December 31, 2010		105,168,366
Cumulative effect of accounting change	(139)				(155)	16	(139)
Ending Balance at Dec. 31, 2010	4,481		1,271	197	2,368	495	4,331	150
Beginning Balance, shares at Dec. 31, 2010		105,168,366
Net earnings	54				88		88	(34)
Other comprehensive income	25					25	25
Allocation of losses of managed investment entities				(35)			(35)	35
Dividends on Common Stock	(17)				(17)		(17)
Shares issued:
Exercise of stock options	11		11				11
Exercise of stock options, shares		436,127
Other benefit plans	7		7				7
Other benefit plans, shares		332,337
Dividend reinvestment plan, shares		4,043
Stock-based compensation expense	3		3				3
Shares acquired and retired	(84)		(30)		(54)		(84)
Shares acquired and retired, shares		(2,457,721)
Other	(2)							(2)
Ending Balance at Mar. 31, 2011	4,478		1,262	162	2,385	520	4,329	149
Ending Balance, shares at Mar. 31, 2011		103,483,152
Beginning Balance at Dec. 31, 2011	4,557		1,219	173	2,439	580	4,411	146
Beginning Balance, shares at Dec. 31, 2011	97,846,402	97,846,402
Net earnings	88				113		113	(25)
Other comprehensive income	138					134	134	4
Allocation of losses of managed investment entities				(28)			(28)	28
Dividends on Common Stock	(17)				(17)		(17)
Shares issued:
Exercise of stock options	14		14				14
Exercise of stock options, shares		551,219
Other benefit plans	5		5				5
Other benefit plans, shares		250,072
Dividend reinvestment plan, shares		3,916
Stock-based compensation expense	4		4				4
Shares acquired and retired	(56)		(19)		(37)		(56)
Shares acquired and retired, shares		(1,473,789)
Other	(1)							(1)
Ending Balance at Mar. 31, 2012	$ 4,732		$ 1,223	$ 145	$ 2,498	$ 714	$ 4,580	$ 152
Ending Balance, shares at Mar. 31, 2012	97,177,820	97,177,820