Earnings Per Share - Weighted Average Shares Outstanding for Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings per share — Basic:
Net income	$ 13,094	$ 8,030	$ 15,742	$ 11,926
Weighted-average shares outstanding — Basic	64,265	63,513	64,143	63,077
Net income per common share — Basic	$ 0.20	$ 0.13	$ 0.25	$ 0.19
Earnings per share — Diluted:
Net income	$ 13,094	$ 8,030	$ 15,742	$ 11,926
Weighted-average shares outstanding — Basic	64,265	63,513	64,143	63,077
Effect of potentially dilutive securities	592	17	219	12
Weighted-average shares outstanding — Diluted	64,857	63,530	64,362	63,089
Net income per common share — Diluted	$ 0.20	$ 0.13	$ 0.24	$ 0.19