Capital Stock (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]
Stock repurchase program, authorized amount	$ 500,000,000	$ 3,900,000,000.0
Available to repurchase common stock		429,300,000
Amount expended on share repurchases in open market transactions		406,326,000	251,008,000	424,849,000
Number of shares repurchased		6,563,986	3,550,817	6,275,470
Average per share price on share repurchases in open market transactions (in dollars per share)		$ 61.90	$ 70.69	$ 67.70
Total tax withholdings for share-based compensation (in shares)		444,657	269,745	182,203
Total tax withholdings for share-based compensation		$ 31,013,000	$ 20,170,000	$ 13,262,000
Preferred stock, shares authorized		5,000,000	5,000,000
Preferred stock, par value		$ 0.01	$ 0.01