CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Statement of Financial Position [Abstract]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount | $	$ 1,568	$ 1,568	$ 1,646
Common stock par value, in dollars per share | $ / shares	$ 0.002	$ 0.002	$ 0.002
Common stock, shares authorized	200,000,000	200,000,000	300,000,000
Common stock, shares issued	173,507,000	173,507,000	170,820,000
Common stock, shares outstanding	173,507,000	173,507,000	170,820,000
Stock split	2	2