Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 3,284	$ 2,720
Weighted-average shares outstanding — basic (in shares)	40,692	38,635
Effect of dilutive securities from stock award plans (in shares)	1,589	1,056
Weighted-average shares outstanding — diluted (in shares)	42,281	39,691
Net income per share - basic (in dollars per share)	$ 0.08	$ 0.07
Net income per share - diluted (in dollars per share)	$ 0.08	$ 0.07
Anti-dilutive weighted-average shares related to stock award plans (in shares)	635	1,113