CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Property, building and equipment, accumulated depreciation	$ 90,652	$ 82,721
Accumulated amortization	$ 18,261	$ 17,659
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	36,525,831	36,355,497
Common stock, shares outstanding (in shares)	31,252,929	31,139,840
Treasury stock at cost, shares (in shares)	5,272,902	5,215,657