CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Trade receivables and contract assets, allowance	$ 5,521	$ 4,886
Stockholders’ equity
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares)	56,868,000	56,128,000
Common stock, shares outstanding (in shares)	56,849,000	56,108,000