CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Trade receivables, allowances	$ 1,921	$ 1,769
STOCKHOLDERS’ EQUITY:
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)
Common stock shares authorized (in shares)	100,000,000	100,000,000
Common stock shares issued (in shares)	50,635,000	50,248,000
Common stock shares outstanding (in shares)	50,635,000	50,248,000
Other
OTHER ASSETS:
Intangibles, accumulated amortization	$ 43,246	$ 38,127
Developed technology
OTHER ASSETS:
Intangibles, accumulated amortization	$ 86,023	$ 72,420