SUPPLEMENTAL GUARANTOR AND NON-GUARANTOR CONSOLIDATING FINANCIAL STATEMENTS - Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Condensed consolidating statements of cash flows
Net cash provided by (used in) operating activities	$ 1,136,445	$ 794,034	$ 1,216,460
Cash flows from investing activities:
Purchases of property and equipment, net of proceeds from disposal	(496,958)	(239,724)	(515,003)
Acquisition and divestiture of businesses, net of cash acquired and cash held in divested business	(910,787)	(66,854)	(233,432)
Other investing activities, net	11,369	64,362	(35,497)
Net cash used in investing activities	(1,396,376)	(242,216)	(783,932)
Cash flows from financing activities:
Proceeds from bank borrowings and long-term debt	884,702	319,542	1,066,653
Repayments of bank borrowings and long-term debt and capital lease obligations	(190,221)	(344,156)	(537,580)
Payments for early repurchase of long-term debt		0	(544,840)
Payments for repurchases of ordinary shares	(420,317)	(415,945)	(475,314)
Proceeds from exercise of stock options	61,278	23,508	28,140
Other financing activities, net	(85,800)	(98,966)	52,149
Net cash provided by (used in) financing activities	249,642	(516,017)	(410,792)
Effect of exchange rates on cash and cash equivalents	(10,549)	(1,121)	(15,095)
Net change in cash and cash equivalents	(20,838)	34,680	6,641
Cash and cash equivalents, beginning of year	1,628,408	1,593,728	1,587,087
Cash and cash equivalents, end of year	1,607,570	1,628,408	1,593,728
Eliminations
Condensed consolidating statements of cash flows
Net cash provided by (used in) operating activities		0	551
Cash flows from investing activities:
Purchases of property and equipment, net of proceeds from disposal	9	(15)	(585)
Investing cash flows from (to) affiliates	4,614,162	2,808,300	2,277,682
Net cash used in investing activities	4,614,171	2,808,285	2,277,097
Cash flows from financing activities:
Financing cash flows from (to) affiliates	(4,614,171)	(2,808,285)	(2,277,648)
Net cash provided by (used in) financing activities	(4,614,171)	(2,808,285)	(2,277,648)
Parent | Reportable legal entities
Condensed consolidating statements of cash flows
Net cash provided by (used in) operating activities	162,275	(73,356)	459,748
Cash flows from investing activities:
Investing cash flows from (to) affiliates	(1,596,210)	(1,703,983)	35,262
Other investing activities, net	(500)	(1,500)
Net cash used in investing activities	(1,596,710)	(1,705,483)	35,262
Cash flows from financing activities:
Proceeds from bank borrowings and long-term debt	824,618	303,000	1,066,359
Repayments of bank borrowings and long-term debt and capital lease obligations	(179,920)	(335,500)	(492,034)
Payments for early repurchase of long-term debt		0	(503,423)
Payments for repurchases of ordinary shares	(420,317)	(415,945)	(475,314)
Proceeds from exercise of stock options	61,278	23,497	28,140
Financing cash flows from (to) affiliates	1,240,145	2,420,952	(277,594)
Net cash provided by (used in) financing activities	1,525,804	1,996,004	(653,866)
Effect of exchange rates on cash and cash equivalents	34,529	(246,908)	57,055
Net change in cash and cash equivalents	125,898	(29,743)	(101,801)
Cash and cash equivalents, beginning of year	608,971	638,714	740,515
Cash and cash equivalents, end of year	734,869	608,971	638,714
Guarantor Subsidiaries | Reportable legal entities
Condensed consolidating statements of cash flows
Net cash provided by (used in) operating activities	427,259	75,775	(126,813)
Cash flows from investing activities:
Purchases of property and equipment, net of proceeds from disposal	(151,383)	(85,876)	(222,197)
Acquisition and divestiture of businesses, net of cash acquired and cash held in divested business	(809,272)	(20,589)	(61,587)
Investing cash flows from (to) affiliates	(1,609,342)	(1,900,810)	(1,237,006)
Other investing activities, net	(31,011)	(13,821)	(10,842)
Net cash used in investing activities	(2,601,008)	(2,021,096)	(1,531,632)
Cash flows from financing activities:
Proceeds from bank borrowings and long-term debt	0	4,737	277
Repayments of bank borrowings and long-term debt and capital lease obligations	(3,059)	(3,127)	(525)
Payments for early repurchase of long-term debt		0	(41,417)
Financing cash flows from (to) affiliates	2,162,840	1,904,164	1,681,559
Other financing activities, net	(8,800)
Net cash provided by (used in) financing activities	2,150,981	1,905,774	1,639,894
Effect of exchange rates on cash and cash equivalents	2,697	(2,643)	2,641
Net change in cash and cash equivalents	(20,071)	(42,190)	(15,910)
Cash and cash equivalents, beginning of year	168,272	210,462	226,372
Cash and cash equivalents, end of year	148,201	168,272	210,462
Non-Guarantor Subsidiaries | Reportable legal entities
Condensed consolidating statements of cash flows
Net cash provided by (used in) operating activities	546,911	791,615	882,974
Cash flows from investing activities:
Purchases of property and equipment, net of proceeds from disposal	(345,584)	(153,833)	(292,221)
Acquisition and divestiture of businesses, net of cash acquired and cash held in divested business	(101,515)	(46,265)	(171,845)
Investing cash flows from (to) affiliates	(1,408,610)	796,493	(1,075,938)
Other investing activities, net	42,880	79,683	(24,655)
Net cash used in investing activities	(1,812,829)	676,078	(1,564,659)
Cash flows from financing activities:
Proceeds from bank borrowings and long-term debt	60,084	11,805	17
Repayments of bank borrowings and long-term debt and capital lease obligations	(7,242)	(5,529)	(45,021)
Proceeds from exercise of stock options	0	11
Financing cash flows from (to) affiliates	1,211,186	(1,516,831)	873,683
Other financing activities, net	(77,000)	(98,966)	52,149
Net cash provided by (used in) financing activities	1,187,028	(1,609,510)	880,828
Effect of exchange rates on cash and cash equivalents	(47,775)	248,430	(74,791)
Net change in cash and cash equivalents	(126,665)	106,613	124,352
Cash and cash equivalents, beginning of year	851,165	744,552	620,200
Cash and cash equivalents, end of year	$ 724,500	$ 851,165	$ 744,552