Consolidated Statement of Changes in Equity (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	Total USD ($)	Total USD ($)	Common Shares	Common Stock and Capital Surplus USD ($)	Retained Earnings Approp. USD ($)	Retained Earnings Unapprop. USD ($)	Accumulated Other Comprehensive Inc. (Loss) USD ($)	Noncontrolling Interests USD ($)
Beginning Balance at Dec. 31, 2013	$ 4,769	$ 4,599		$ 1,213	$ 49	$ 2,777	$ 560	$ 170
Beginning Balance, shares at Dec. 31, 2013			89,513,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	107	103				103		4
Other comprehensive income	120	117					117	3
Allocation of losses of managed investment entities	0	0			0			0
Dividends on Common Stock	(19)	(19)				(19)
Shares issued:
Exercise of stock options, shares			323,473
Exercise of stock options	11	11		11
Other benefit plans, shares			192,525
Other benefit plans	5	5		5
Dividend reinvestment plan, shares			3,343
Stock-based compensation expense	5	5		5
Shares acquired and retired, shares			(419,938)
Shares acquired and retired	(24)	(24)		(6)		(18)
Shares exchanged - benefit plans, shares			(23,790)
Shares exchanged - benefit plans	(1)	(1)				(1)
Ending Balance at Mar. 31, 2014	4,973	4,796		1,228	49	2,842	677	177
Ending Balance, shares at Mar. 31, 2014			89,588,999
Beginning Balance at Dec. 31, 2014	5,054	4,879		1,240	(2)	2,914	727	175
Beginning Balance, shares at Dec. 31, 2014	87,708,793		87,708,793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change for variable interest entities	2	2			2
Net earnings	25	19				19		6
Other comprehensive income	50	49					49	1
Dividends on Common Stock	(22)	(22)				(22)
Shares issued:
Exercise of stock options, shares			489,001
Exercise of stock options	20	20		20
Other benefit plans, shares			233,224
Other benefit plans	4	4		4
Dividend reinvestment plan, shares			3,606
Dividend reinvestment plan	0	0		0
Stock-based compensation expense	5	5		5
Shares acquired and retired, shares			(516,276)
Shares acquired and retired	(31)	(31)		(8)		(23)
Shares exchanged - benefit plans, shares			(32,633)
Shares exchanged - benefit plans	(2)	(2)				(2)
Other	(5)							(5)
Ending Balance at Mar. 31, 2015	$ 5,100	$ 4,923		$ 1,261	$ 0	$ 2,886	$ 776	$ 177
Ending Balance, shares at Mar. 31, 2015	87,885,715		87,885,715