Stock Based Compensation (Restricted Stock Units Activity) (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Outstanding at Beginning of Year	257,583
Shares, Granted	200,923
Shares, Vested	(207,126)
Shares, Canceled	(36,399)
Shares, Outstanding at End of Year	214,981	257,583
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Shares, Outstanding at Beginning of Year, Weighted Average Grant Date Fair Value	$ 46.58
Shares, Granted, Weighted Average Grant Date Fair Value	56.24	$ 49.34	$ 44.33
Shares, Vested, Weighted Average Grant Date Fair Value	51.34
Shares, Canceled, Weighted Average Grant Date Fair Value	50.23
Shares, Outstanding at End of Year, Weighted Average Grant Date Fair Value	$ 50.41	$ 46.58
Shares, Outstanding at End of Year, Weighted Average Remaining Years Contractual Term	1 year 1 month 6 days
Shares, Outstanding at End of Year, Aggregate Intrinsic Value	$ 12,694,628