CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 16,288	$ 30,384	$ 55,412	$ 86,477
Other comprehensive income (loss):
Foreign currency translation adjustments	34	54	585	128
Unrealized gains (losses) on cash flow hedges:
Unrealized cash flow hedge gains (losses) arising during the period	1,330	508	(3,484)	3,604
Net (gains) losses reclassified into income for revenue hedges	(1,739)	(1,220)	(7,474)	(61)
Net (gains) losses reclassified into income for cost of revenue hedges	1,238	63	3,182	(149)
Net unrealized gains (losses) on cash flow hedges	829	(649)	(7,776)	3,394
Unrealized holding gains (losses) during the period	(637)	(258)	(845)	(223)
Aggregate income tax benefit (expense) of the above items	150	66	348	(13)
Other comprehensive income (loss)	376	(787)	(7,688)	3,286
Comprehensive income	$ 16,664	$ 29,597	$ 47,724	$ 89,763