Repurchases of Common Stock (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014 Open Market Share Repurchase [Member]	Jan. 30, 2014 Open Market Share Repurchase [Member]	Jan. 30, 2014 Tender Offer [Member]	Sep. 30, 2014 Tender Offer [Member]
Class of Stock Disclosures [Abstract]
Additional repurchase program, authorized amount				$ 500,000,000	$ 350,000,000.0
Stock Repurchase Program, Number of Shares Authorized to be Repurchased, Option to Increase Repurchase Amount, Percentage of Outstanding Shares					2.00%
Accelerated Share Repurchases [Line Items]
Repurchases of common stock (in shares)			2,633,526			5,291,701
Treasury Stock Acquired, Average Cost Per Share		$ 68.31	$ 64.77			$ 70.07
Treasury Stock, Value, Acquired, Excluding Fees		541,400,000
Repurchases of common stock	70,587,000	545,156,000	170,582,000			370,789,000	[1]
Professional fees paid						$ 3,800,000

[1] Excludes expenses of $3.8 million associated with the tender offer.