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 ($)	Retained Earnings Approp. USD ($)	Retained Earnings Unapprop. USD ($)	Accumulated Other Comprehensive Inc. (Loss) USD ($)	Total USD ($)	Noncontrolling Interests USD ($)
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
Net earnings	88				113		113	(25)
Other comprehensive income	138					134	134	4
Allocation of losses of managed investment entities	0			(28)			(28)	28
Dividends on Common Stock	(17)				(17)		(17)
Shares issued:
Exercise of stock options, shares		551,219
Exercise of stock options	14		14				14
Other benefit plans, shares		250,072
Other benefit plans	5		5				5
Dividend reinvestment plan, shares		3,916
Dividend reinvestment plan	0		0				0
Stock-based compensation expense	4		4				4
Shares acquired and retired, shares		(1,473,789)
Shares acquired and retired	(56)		(19)		(37)		(56)
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
Beginning Balance at Dec. 31, 2012	4,748		1,152	75	2,520	831	4,578	170
Beginning Balance, shares at Dec. 31, 2012	88,979,303	88,979,303
Net earnings	113				120		120	(7)
Other comprehensive income	39					38	38	1
Allocation of losses of managed investment entities	0			(11)			(11)	11
Dividends on Common Stock	(17)				(17)		(17)
Shares issued:
Exercise of stock options, shares		646,136
Exercise of stock options	21		21				21
Other benefit plans, shares		344,736
Other benefit plans	4		4				4
Dividend reinvestment plan, shares		3,986
Stock-based compensation expense	4		4				4
Shares acquired and retired, shares		(61,586)
Shares acquired and retired	(3)		(1)		(2)		(3)
Shares exchanged - benefit plans, shares		(29,353)
Shares exchanged - benefit plans	(1)				(1)		(1)
Ending Balance at Mar. 31, 2013	$ 4,908		$ 1,180	$ 64	$ 2,620	$ 869	$ 4,733	$ 175
Ending Balance, shares at Mar. 31, 2013	89,883,222	89,883,222