CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Property and equipment, accumulated depreciation	$ 96,937	$ 95,024
Intangible assets, accumulated amortization	$ 19,900	$ 22,973
Preferred stock, par value (usd per share)	$ 0.001	$ 0.001
Preferred stock, authorized (shares)	5,000,000	5,000,000
Preferred stock, issued (shares)	0	0
Preferred stock, outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, authorized (shares)	60,000,000	60,000,000
Common stock, issued (shares)	37,674,868	37,470,212
Common stock, outstanding (shares)	32,509,969	32,814,278
Treasury stock at cost (shares)	5,164,899	4,655,934