Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Weighted-average shares outstanding for basic and diluted net income per share
Net income (in dollars)	$ 4,750	$ 10,121	$ 9,913	$ 23,066
Basic net income per share:
Weighted-average shares outstanding - Basic	60,247	59,734	60,238	59,647
Basic net income per common share (in usd per share)	$ 0.08	$ 0.17	$ 0.16	$ 0.39
Diluted net income per share:
Weighted-average shares outstanding - Basic	60,247	59,734	60,238	59,647
Effect of potentially dilutive securities	541	17	544	16
Weighted-average shares outstanding - Diluted	60,788	59,751	60,782	59,663
Diluted net income per common share (in usd per share)	$ 0.08	$ 0.17	$ 0.16	$ 0.39