Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 710	$ (1,109)	$ 820	$ (11,791)
Other comprehensive income (loss):
Unrealized gain (loss) on investments, net of tax	(2)		(1)	12
Unrealized gain on currency translation				8
Other comprehensive income (loss)	(2)		(1)	20
Comprehensive income (loss)	$ 708	$ (1,109)	$ 819	$ (11,771)