CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (49,504)	$ 22,221	$ (10,723)	$ 63,082
Other comprehensive income (loss):
Foreign currency translation adjustments	0	82	257	(168)
Unrealized gains (losses) on cash flow hedges:
Unrealized cash flow hedge gains (losses) arising during the period	(446)	2,090	(5,093)	2,394
Net (gains) losses reclassified into income for revenue hedges	1,357	(2,178)	2,506	(3,163)
Net (gains) losses reclassified into income for cost of revenue hedges	(61)	756	(193)	2,072
Net unrealized gains (losses) on cash flow hedges	850	668	(2,780)	1,303
Unrealized holding gains (losses) during the period	(658)	(628)	(449)	(586)
Aggregate income tax benefit (expense) of the above items	181	156	182	130
Other comprehensive income (loss)	373	278	(2,790)	679
Comprehensive income (loss)	$ (49,131)	$ 22,499	$ (13,513)	$ 63,761