Consolidated Statement of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Total	Common Shares	Common Stock and Capital Surplus	Retained Earnings Approp.	Retained Earnings Unapprop.	Accumulated Other Comprehensive Inc. (Loss)	Noncontrolling Interests
Beginning Balance, shares at Dec. 31, 2013			89,513,386
Beginning Balance at Dec. 31, 2013	$ 4,769	$ 4,599		$ 1,213	$ 49	$ 2,777	$ 560	$ 170
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	281	325				325		(44)
Other comprehensive income (loss)	161	158					158	3
Allocation of losses of managed investment entities	0	(47)			(47)			47
Dividends on Common Stock	(59)	(59)				(59)
Shares issued:
Exercise of stock options, shares			972,847
Exercise of stock options	34	34		34
Other benefit plans, shares			227,782
Other benefit plans	7	7		7
Dividend reinvestment plan, shares			9,749
Dividend reinvestment plan	1	1		1
Stock-based compensation expense	14	14		14
Shares acquired and retired, shares			(2,209,007)
Shares acquired and retired	(127)	(127)		(31)		(96)
Shares exchanged - benefit plans, shares			(23,790)
Shares exchanged - benefit plans	(1)	(1)				(1)
Other	(2)							(2)
Ending Balance, shares at Sep. 30, 2014			88,490,967
Ending Balance at Sep. 30, 2014	5,078	4,904		1,238	2	2,946	718	174
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change for variable interest entities	$ 2	2			2
Beginning Balance, shares at Dec. 31, 2014	87,708,793		87,708,793
Beginning Balance at Dec. 31, 2014	$ 5,054	4,879		1,240	(2)	2,914	727	175
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	240	223				223		17
Other comprehensive income (loss)	(270)	(266)					(266)	(4)
Dividends on Common Stock	(66)	(66)				(66)
Shares issued:
Exercise of stock options, shares			1,157,288
Exercise of stock options	46	46		46
Other benefit plans, shares			268,947
Other benefit plans	6	6		6
Dividend reinvestment plan, shares			10,359
Dividend reinvestment plan	1	1		1
Stock-based compensation expense	14	14		14
Shares acquired and retired, shares			(1,767,240)
Shares acquired and retired	(113)	(113)		(25)		(88)
Shares exchanged - benefit plans, shares			(33,795)
Shares exchanged - benefit plans	(2)	(2)				(2)
Forfeitures of restricted stock, shares			(17,180)
Forfeitures of restricted stock	0	0		0
Other	$ (6)							(6)
Ending Balance, shares at Sep. 30, 2015	87,327,172		87,327,172
Ending Balance at Sep. 30, 2015	$ 4,906	$ 4,724		$ 1,282	$ 0	$ 2,981	$ 461	$ 182