CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (86,709)	$ 19,953	$ (72,238)	$ 38,781
Other comprehensive income (loss):
Foreign currency translation adjustments	(1,815)	57	(1,815)	257
Unrealized gains (losses) on cash flow hedges:
Unrealized cash flow hedge gains (losses) arising during the period	813	(2,302)	4,769	(4,647)
Net (gains) losses reclassified into income for revenue hedges	(900)	1,131	(1,149)	1,149
Net (gains) losses reclassified into income for cost of revenue hedges	0	(174)	(79)	(132)
Net (gains) losses reclassified into income for interest rate swap	977	0	977	0
Net unrealized gains (losses) on cash flow hedges	890	(1,345)	4,518	(3,630)
Unrealized holding gains (losses) during the period	0	133	198	209
Aggregate income tax benefit (expense) of the above items	8	(19)	(102)	1
Other comprehensive income (loss)	(917)	(1,174)	2,799	(3,163)
Comprehensive income (loss)	$ (87,626)	$ 18,779	$ (69,439)	$ 35,618