Share-based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Options, Outstanding [Roll Forward]
Stock options outstanding, ending balance	162,000
Stock options, Exercisable	80,250
Stock Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock options, Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 37.68	$ 30.73	$ 15.17
Stock options, Granted, Weighted Average Exercise Price (in dollars per share)	42.56	53.90	49.22
Stock options, Exercised, Weighted Average Exercise Price (in dollars per share)	15.65	14.90	11.38
Stock options, Canceled, Weighted Average Exercise Price (in dollars per share)
Stock options, Weighted Average Exercise Price, ending balance (in dollars per share)	42.75	$ 37.68	$ 30.73	$ 15.17
Stock options, Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 38.21
Stock Options, Additional Disclosures [Abstract]
Stock options outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 20 days	2 years 11 months 8 days	3 years 3 months 12 days	2 years 3 months 25 days
Stock options, Exercisable, Weighted Average Remaining Contractual Term (in years)	2 years 1 day
Stock options outstanding, Aggregate Intrinsic Value	$ 0	$ 6,152	$ 2,882	$ 2,465
Stock options, Exercisable, Aggregate Intrinsic Value	49
Proceeds from stock options exercised	439	52	824
Stock Options
Stock Options, Additional Disclosures [Abstract]
Stock options exercised in period, intrinsic value	$ 900	$ 169	$ 3,200
Within Plans
Stock Options, Outstanding [Roll Forward]
Stock options outstanding, beginning balance	147,999	109,499	139,878
Stock options, Granted	42,000	42,000	42,000
Stock options, Exercised	(27,999)	(3,500)	(72,379)
Stock options, Canceled	0	0	0
Stock options outstanding, ending balance	162,000	147,999	109,499	139,878
Stock options, Exercisable	80,250
Employee and Non-employees
Stock Options, Outstanding [Roll Forward]
Stock options, Granted	0	0	0