Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Weighted-average shares outstanding for basic and diluted net income per share
Net income	$ (16,322)	$ 7,302	$ 8,315	$ 6,362	$ 10,743	$ 6,676	$ 4,750	$ 5,163	$ 5,657	$ 27,332	$ 15,680
Weighted-average shares outstanding - Basic	60,899	60,867	60,461	60,312	60,288	60,272	60,247	60,230	60,635	60,259	59,918
Basic net income per share:
Basic net income per common share	$ (0.27)	$ 0.12	$ 0.14	$ 0.11	$ 0.18	$ 0.11	$ 0.08	$ 0.09	$ 0.09	$ 0.45	$ 0.26
Diluted net income per share:
Weighted-average shares outstanding - Basic	60,899	60,867	60,461	60,312	60,288	60,272	60,247	60,230	60,635	60,259	59,918
Effect of potentially dilutive securities									598	590	216
Weighted-average shares outstanding - Diluted	60,899	61,279	61,194	61,064	60,956	60,855	60,788	60,770	61,233	60,849	60,134
Diluted net income per common share	$ (0.27)	$ 0.12	$ 0.14	$ 0.10	$ 0.18	$ 0.11	$ 0.08	$ 0.08	$ 0.09	$ 0.45	$ 0.26