Stock Based Compensation (Stock Option Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Beginning of Year	2,615,166
Options, Exercised	519,250
Options, Canceled/Forfeited	20,066
Options, End of Year	2,075,850
Options, Exercisable at End of Year	2,075,850
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options, Beginning of Year, Weighted Average Exercise Price	$ 34.43
Options, Exercised, Weighted Average Exercise Price	$ 30.51
Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 39.88
Options, End of Year, Weighted Average Exercise Price	$ 35.35
Options, Exercisable at End of Year, Weighted Average Exercise Price	$ 35.35
Options, Outstanding at End of Year, Weighted Average Remaining Years Contractual Term	3 years 9 months 18 days
Options, Exercisable at End of Year, Weighted Average Remaining Years Contractual Term	3 years 9 months 18 days
Options, Outstanding at End of Year, Aggregate Intrinsic Value	$ 15,016,886
Options, Exercisable at End of Year, Aggregate Intrinsic Value	$ 15,016,886