Supplemental Schedule of Noncash Financing Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested, Shares	6,134	17,185
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested	$ (398)	$ (998)	$ (2,202)
Common Stock Repurchase not settled, Shares		109,475	25,000
Common Stock Repurchase not settled, Value		$ 6,400	$ 820