Organization and Summary of Significant Accounting Policies - Weighted Average Number of Shares Outstanding and Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator for basic and diluted earnings per share:
Net income (loss)	$ (873)	$ (30,759)	$ 4,074	$ 6,104	$ 738	$ 6,419	$ (27,558)	$ 13,261
Denominator:
Weighted average shares outstanding (in shares)	63,496			59,278			61,159	59,128
Dilutive effect of stock-based awards (in shares)				781				810
Diluted weighted average shares outstanding (in shares)	63,496			60,059			61,159	59,938
Anti-dilutive stock-based awards excluded (in shares)	12,793			12,477			12,904	12,546
Net income (loss) per common share:
Basic (in dollars per share)	$ (0.01)			$ 0.10			$ (0.45)	$ 0.22
Diluted (in dollars per share)	$ (0.01)			$ 0.10			$ (0.45)	$ 0.22