Stock Based Compensation (Stock Option Activity) (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Beginning of Year | shares	1,707,250
Options, Exercised | shares	677,350
Options, Canceled/Forfeited | shares	0
Options, End of Year | shares	1,029,900
Options, Exercisable at End of Year | shares	1,029,900
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	$ 36.00
Options, Exercised, Weighted Average Exercise Price | $ / shares	33.06
Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price | $ / shares	0.00
Options, End of Year, Weighted Average Exercise Price | $ / shares	37.93
Options, Exercisable at End of Year, Weighted Average Exercise Price | $ / shares	$ 37.93
Options, Outstanding at End of Year, Weighted Average Remaining Years Contractual Term	2 years
Options, Exercisable at End of Year, Weighted Average Remaining Years Contractual Term	2 years
Options, Outstanding at End of Year, Aggregate Intrinsic Value | $	$ 7,640,178
Options, Exercisable at End of Year, Aggregate Intrinsic Value | $	$ 7,640,178