Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Beginning Balance at Dec. 31, 2012		$ 394	$ 1,134	$ 4,021	$ 1,129	$ (1,225)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		3	36			10
Share-based compensation			18
Other			3			5
Net Income	$ 517			517
Dividends declared				(270)
Other comprehensive income	375				375
Shares acquired - share repurchase authorization						(52)
Shares acquired - share-based compensation plans						(28)
Ending Balance at Dec. 31, 2013	6,070	$ 397	1,191	4,268	1,504	(1,290)
Beginning Balance (in shares) at Dec. 31, 2012		162,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		1,600
Shares acquired—share repurchase authorization (in shares)		(1,000)
Shares acquired - share-based compensation plans (in shares)		(600)
Other (in shares)		200
Ending Balance (in shares) at Dec. 31, 2013		163,100
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		$ 0	0			37
Share-based compensation			19
Other			4			6
Net Income	525			525
Dividends declared				(288)
Other comprehensive income	240				240
Shares acquired - share repurchase authorization						(21)
Shares acquired - share-based compensation plans						(19)
Ending Balance at Dec. 31, 2014	$ 6,573	$ 397	1,214	4,505	1,744	(1,287)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		1,300
Shares acquired—share repurchase authorization (in shares)		(500)
Shares acquired - share-based compensation plans (in shares)		(400)
Other (in shares)		200
Ending Balance (in shares) at Dec. 31, 2014	198,300	163,700
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		$ 0	(7)			41
Share-based compensation			20
Other			5			7
Net Income	$ 634			634
Dividends declared				(377)
Other comprehensive income	(400)				(400)
Shares acquired - share repurchase authorization						(53)
Shares acquired - share-based compensation plans						(16)
Ending Balance at Dec. 31, 2015	$ 6,427	$ 397	$ 1,232	$ 4,762	$ 1,344	$ (1,308)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)	996	1,300
Shares acquired—share repurchase authorization (in shares)		(1,000)
Shares acquired - share-based compensation plans (in shares)		(300)
Other (in shares)		200
Ending Balance (in shares) at Dec. 31, 2015	198,300	163,900