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, 2013		$ 397	$ 1,191	$ 4,268	$ 1,504	$ (1,290)
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 (loss)	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)
Beginning Balance (in shares) at Dec. 31, 2013		163,100
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		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 (loss)	(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)		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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		$ 0	(8)			36
Share-based compensation			23
Other			5			5
Net Income	$ 591			591
Dividends declared				(316)
Other comprehensive income (loss)	349				349
Shares acquired - share repurchase authorization						(39)
Shares acquired - share-based compensation plans						(13)
Ending Balance at Dec. 31, 2016	$ 7,060	$ 397	$ 1,252	$ 5,037	$ 1,693	$ (1,319)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)	863	1,000
Shares acquired—share repurchase authorization (in shares)		(500)
Shares acquired - share-based compensation plans (in shares)		(200)
Other (in shares)		200
Ending Balance (in shares) at Dec. 31, 2016	198,300	164,400