Basic and Diluted Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net income (loss)	$ 220,606	$ (12,205)
Weighted-average shares outstanding:
Basic (in shares)	47,381	46,349
Assumed conversion of employee stock grants (in shares)	2,631	0
Assumed conversion of warrants (in shares)	7,719	0
Diluted (in shares)	57,731	46,349
Net income (loss) per basic share (in usd per share)	$ 4.66	$ (0.26)
Net income (loss) per diluted share (in usd per share)	$ 3.82	$ (0.26)
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
Document Period End Date	Jun. 30, 2017
Common stock equivalents (in shares)	133	2,330
Assumed conversion of warrants
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
Common stock equivalents (in shares)	0	4,853