Stock Based Compensation (Stock Option Activity) (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Beginning of Year | shares	2,075,850
Options, Exercised | shares	368,600
Options, Canceled/Forfeited | shares	0
Options, End of Year | shares	1,707,250
Options, Exercisable at End of Year | shares	1,707,250
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 | $ / shares	$ 35.35
Options, Exercised, Weighted Average Exercise Price | $ / shares	32.37
Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price | $ / shares	0.00
Options, End of Year, Weighted Average Exercise Price | $ / shares	36.00
Options, Exercisable at End of Year, Weighted Average Exercise Price | $ / shares	$ 36.00
Options, Outstanding at End of Year, Weighted Average Remaining Years Contractual Term	2 years 9 months 18 days
Options, Exercisable at End of Year, Weighted Average Remaining Years Contractual Term	2 years 9 months 18 days
Options, Outstanding at End of Year, Aggregate Intrinsic Value | $	$ 8,120,788
Options, Exercisable at End of Year, Aggregate Intrinsic Value | $	$ 8,120,788