SUPPLEMENTAL GUARANTOR AND NON-GUARANTOR CONSOLIDATING FINANCIAL STATEMENTS - Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Condensed consolidating statements of comprehensive income (loss)
Net income	$ 444,081	$ 600,801	$ 365,594
Other comprehensive income (loss):
Foreign currency translation adjustments, net of zero tax	17,846	(18,932)	(34,683)
Unrealized gain (loss) on derivative instruments and other, net of zero tax	26,744	(35,417)	(13,992)
Comprehensive income	488,671	546,452	316,919
Eliminations
Condensed consolidating statements of comprehensive income (loss)
Net income	(481,493)	(941,688)	29,885
Other comprehensive income (loss):
Foreign currency translation adjustments, net of zero tax	32,714	(478,070)	178,917
Unrealized gain (loss) on derivative instruments and other, net of zero tax	(41,939)	69,186	19,214
Comprehensive income	(490,718)	(1,350,572)	228,016
Parent | Reportable legal entities
Condensed consolidating statements of comprehensive income (loss)
Net income	444,081	600,801	365,594
Other comprehensive income (loss):
Foreign currency translation adjustments, net of zero tax	17,846	(18,932)	(34,683)
Unrealized gain (loss) on derivative instruments and other, net of zero tax	26,744	(35,417)	(13,992)
Comprehensive income	488,671	546,452	316,919
Guarantor Subsidiaries | Reportable legal entities
Condensed consolidating statements of comprehensive income (loss)
Net income	85,744	195,591	(13,621)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of zero tax	(16,979)	256,652	(89,282)
Unrealized gain (loss) on derivative instruments and other, net of zero tax	15,195	(33,769)	(5,221)
Comprehensive income	83,960	418,474	(108,124)
Non-Guarantor Subsidiaries | Reportable legal entities
Condensed consolidating statements of comprehensive income (loss)
Net income	395,749	746,097	(16,264)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of zero tax	(15,735)	221,418	(89,635)
Unrealized gain (loss) on derivative instruments and other, net of zero tax	26,744	(35,417)	(13,993)
Comprehensive income	$ 406,758	$ 932,098	$ (119,892)