Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable - net of allowance	$ 75	$ 2,754
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, authorized	5,000,000	5,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	100,000,000	100,000,000
Common stock, issued	56,240,000	55,066,000
Common stock, outstanding	56,240,000	55,066,000