Basic and Diluted Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss)	$ 16,602	$ 40,806	$ 41,682	$ 113,167
Weighted-average shares outstanding:
Basic (in shares)	58,646	58,010	58,509	57,717
Assumed conversion of employee stock grants (in shares)	883	1,101	819	1,399
Diluted (in shares)	59,529	59,111	59,328	59,116
Net income (loss) per basic share (in usd per share)	$ 0.28	$ 0.70	$ 0.71	$ 1.96
Net income (loss) per diluted share (in usd per share)	$ 0.28	$ 0.69	$ 0.70	$ 1.91
Common stock equivalents that could potentially dilute net income per basic share in the future, but were not included in the computation of diluted earnings per share because the impact would have been antidilutive
Payments of Ordinary Dividends, Common Stock	$ 0	$ 2,873	$ 5,803	$ 2,873
Common stock equivalents (in shares)	88	76	30	0