Long-Term Equity Compensation (Summary of Stock Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Oustanding beginning balance, Number of Options	3,313,356
Granted, Number of Options	0	0	0
Exercised, Number of Options	(1,320,086)
Forfeited or expired, Number of Options	(41,059)
Oustanding ending balance, Number of Options	1,952,211	3,313,356
Outstanding beginning balance, Weighted Average Exercise Price	$ 31.33
Granted, Weighted Average Exercise Price	$ 0.00
Exercised, Weighted Average Exercise Price	$ 28.52
Forfeited or expired, Weighted Average Exercise Price	$ 42.01
Outstanding ending balance, Weighted Average Exercise Price	$ 33.01	$ 31.33
Outstanding balance, Weighted Average Remaining Contractual Term (Years)	2 years 7 days
Oustanding balance, Agregate Intrinsic Value	$ 40,278,961
Vested or expected to vest, Number of Options	1,952,045
Vested or expected to vest, Weighted Average Exercise Price	$ 33.01
Vested or expected to vest, Weighted Average Remaining Contractual Term (Years)	2 years 7 days
Vested or expected to vest, Aggregate Intrinsic Value	40,275,247
Exercisable, Number of Options	1,944,500
Exercisable, Weighted Average Exercise Price	$ 33.01
Exercisable, Weighted Average Remaining Contractual Term (Years)	2 years 4 days
Exercisable, Aggregate Intrinsic Value	$ 40,109,115