CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, reserves	$ 4,392	$ 8,762
Stockholders’ equity:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	220,000	220,000
Common stock, shares issued (in shares)	127,626	121,266
Treasury stock, at cost, shares (in shares)	3,494	3,670