CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets:
Fixed assets, accumulated depreciation	$ 20,114	$ 19,752
Intangible assets, accumulated amortization	$ 3,423	$ 3,359
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	11,422,620	11,366,526
Common stock, shares outstanding (in shares)	7,377,778	7,478,094
Treasury stock (in shares)	4,044,842	3,888,432