Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss)	$ 5,756	$ (18,819)	$ 172	$ (44,828)
Shares used in computing net income (loss) per share:
Weighted-average basic shares outstanding (in shares)	22,849	18,625	21,064	18,567
Effect of dilutive securities (in shares)	27	0	24	0
Weighted-average common shares outstanding-diluted (in shares)	22,876	18,625	21,088	18,567
Earnings (loss) per common share:
Earnings (loss) per share of common stock — basic (in dollars per share)	$ 0.25	$ (1.01)	$ 0.01	$ (2.41)
Earnings (loss) per share of common stock — diluted (in dollars per share)	$ 0.25	$ (1.01)	$ 0.01	$ (2.41)
Antidilutive shares (in shares)	200	3,600	1,800	3,900