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, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income (loss)	[1],[2]	$ 40,806	$ 18,589	$ 113,167	$ 251,847
Weighted-average shares outstanding:
Basic (in shares)		58,010	56,778	57,717	51,340
Assumed conversion of employee stock grants (in shares)		1,101	2,159	1,399	2,384
Assumed conversion of warrants (in shares)		0	0	0	4,707
Diluted (in shares)		59,111	58,937	59,116	58,431
Net income (loss) per basic share (in usd per share)		$ 0.70	$ 0.33	$ 1.96	$ 4.91
Net income (loss) per diluted share (in usd per share)		$ 0.69	$ 0.32	$ 1.91	$ 4.31
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				$ 2,873	$ 0
Common stock equivalents (in shares)		76	164	0	134

[1] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.

[2] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.