CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ 1,821	$ 1,646
Preferred stock par value, in dollars per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	400,000	400,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock par value, in dollars per share	$ 0.002	$ 0.002
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	172,440,000	170,820,000
Common stock, shares outstanding	172,440,000	170,820,000