Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable and unbilled receivables, net of allowance	$ 4,286	$ 3,227
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	52,677,000	51,277,000
Common stock, shares outstanding (in shares)	42,783,000	42,132,000
Treasury stock, shares outstanding (in shares)	9,894,000	9,145,000