Repurchases of Common Stock (Accelerated Stock Repurchase Program) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Accelerated Share Repurchases [Line Items]
Treasury Stock Acquired, Average Cost Per Share		$ 68.31
Repurchases of common stock	$ 70,587	$ 545,156
Open Market Share Repurchase [Member]
Accelerated Share Repurchases [Line Items]
Total shares delivered from DSB Agreement		2,633,526
Treasury Stock Acquired, Average Cost Per Share		$ 64.77
Repurchases of common stock		170,582
Tender Offer [Member]
Accelerated Share Repurchases [Line Items]
Total shares delivered from DSB Agreement		5,291,701
Treasury Stock Acquired, Average Cost Per Share		$ 70.07
Repurchases of common stock		$ 370,789	[1]

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