SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (19,544)	$ 11,537	$ 118,231
Capital expenditures	(46,287)	(135,110)	(372,375)
Proceeds from asset dispositions	48,740	18,471	60,035
Investment in unconsolidated affiliate	0	0	(4,410)
Proceeds from OEM cost recoveries	94,463	0	0
Deposit received on aircraft held for sale	0	290	0
Net cash provided by (used in) investing activities	96,916	(116,349)	(316,750)
Proceeds from borrowings	896,874	708,267	928,802
Payment of contingent consideration	0	(10,000)	(9,453)
Debt issuance costs	(20,560)	(8,010)	(5,139)
Repayment of debt and debt redemption premiums	(671,567)	(570,328)	(677,003)
Purchase of 4½% Convertible Senior Notes call option	(40,393)	0	0
Proceeds from issuance of warrants	30,259	0	0
Partial prepayment of put/call obligation	(49)	(49)	(55)
Acquisition of noncontrolling interests	0	0	(7,309)
Dividends paid to noncontrolling interest	(331)	(2,533)	(153)
Dividends paid	(2,465)	(9,831)	(38,076)
Increases (decreases) in cash related to intercompany advances and debt	0	0	0
Repurchases for tax withholdings on vesting of equity awards	(2,740)	(835)	(2,205)
Net cash provided by financing activities	189,028	106,681	189,409
Effect of exchange rate changes on cash and cash equivalents	17,167	(9,523)	9,274
Net increase (decrease) in cash and cash equivalents	283,567	(7,654)	164
Cash and cash equivalents at beginning of period	96,656	104,310	104,146
Cash and cash equivalents at end of period	380,223	96,656	104,310
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0	0
Capital expenditures	77,480	0	0
Proceeds from asset dispositions	(77,480)	0	0
Investment in unconsolidated affiliate			0
Proceeds from OEM cost recoveries	0
Deposit received on aircraft held for sale		0
Net cash provided by (used in) investing activities	0	0	0
Proceeds from borrowings	0	0	0
Payment of contingent consideration		0	0
Debt issuance costs	0	0	0
Repayment of debt and debt redemption premiums	0	0	0
Purchase of 4½% Convertible Senior Notes call option	0
Proceeds from issuance of warrants	0
Partial prepayment of put/call obligation	0	0	0
Acquisition of noncontrolling interests			0
Dividends paid to noncontrolling interest	0	0	0
Dividends paid	0	0	0
Increases (decreases) in cash related to intercompany advances and debt	0	0	0
Repurchases for tax withholdings on vesting of equity awards	0	0	0
Net cash provided by financing activities	0	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(125,596)	(100,841)	(94,292)
Capital expenditures	(8,902)	(16,544)	(31,223)
Proceeds from asset dispositions	0	0	0
Investment in unconsolidated affiliate			0
Proceeds from OEM cost recoveries	0
Deposit received on aircraft held for sale		0
Net cash provided by (used in) investing activities	(8,902)	(16,544)	(31,223)
Proceeds from borrowings	665,106	300,600	908,225
Payment of contingent consideration		0	0
Debt issuance costs	(11,677)	(2,925)	(5,139)
Repayment of debt and debt redemption premiums	(621,902)	(533,500)	(649,650)
Purchase of 4½% Convertible Senior Notes call option	(40,393)
Proceeds from issuance of warrants	30,259
Partial prepayment of put/call obligation	(49)	(49)	(55)
Acquisition of noncontrolling interests			0
Dividends paid to noncontrolling interest	0	0	0
Dividends paid	217,802	13,780	(38,076)
Increases (decreases) in cash related to intercompany advances and debt	171,886	308,455	(52,470)
Repurchases for tax withholdings on vesting of equity awards	(2,740)	(835)	(2,205)
Net cash provided by financing activities	408,292	85,526	160,630
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	273,794	(31,859)	35,115
Cash and cash equivalents at beginning of period	3,382	35,241	126
Cash and cash equivalents at end of period	277,176	3,382	35,241
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	61,757	18,359	104,989
Capital expenditures	(9,754)	(25,756)	(239,773)
Proceeds from asset dispositions	85,785	16,346	50,780
Investment in unconsolidated affiliate			0
Proceeds from OEM cost recoveries	0
Deposit received on aircraft held for sale		290
Net cash provided by (used in) investing activities	76,031	(9,120)	(188,993)
Proceeds from borrowings	0	309,889	0
Payment of contingent consideration		0	0
Debt issuance costs	(552)	(4,199)	0
Repayment of debt and debt redemption premiums	(18,512)	(5,016)	0
Purchase of 4½% Convertible Senior Notes call option	0
Proceeds from issuance of warrants	0
Partial prepayment of put/call obligation	0	0	0
Acquisition of noncontrolling interests			0
Dividends paid to noncontrolling interest	0	0	0
Dividends paid	0	(21,226)	0
Increases (decreases) in cash related to intercompany advances and debt	(110,119)	(291,781)	86,513
Repurchases for tax withholdings on vesting of equity awards	0	0	0
Net cash provided by financing activities	(129,183)	(12,333)	86,513
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	8,605	(3,094)	2,509
Cash and cash equivalents at beginning of period	299	3,393	884
Cash and cash equivalents at end of period	8,904	299	3,393
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	44,295	94,019	107,534
Capital expenditures	(105,111)	(92,810)	(101,379)
Proceeds from asset dispositions	40,435	2,125	9,255
Investment in unconsolidated affiliate			(4,410)
Proceeds from OEM cost recoveries	94,463
Deposit received on aircraft held for sale		0
Net cash provided by (used in) investing activities	29,787	(90,685)	(96,534)
Proceeds from borrowings	231,768	97,778	20,577
Payment of contingent consideration		(10,000)	(9,453)
Debt issuance costs	(8,331)	(886)	0
Repayment of debt and debt redemption premiums	(31,153)	(31,812)	(27,353)
Purchase of 4½% Convertible Senior Notes call option	0
Proceeds from issuance of warrants	0
Partial prepayment of put/call obligation	0	0	0
Acquisition of noncontrolling interests			(7,309)
Dividends paid to noncontrolling interest	(331)	(2,533)	(153)
Dividends paid	(220,267)	(2,385)	0
Increases (decreases) in cash related to intercompany advances and debt	(61,767)	(16,674)	(34,043)
Repurchases for tax withholdings on vesting of equity awards	0	0	0
Net cash provided by financing activities	(90,081)	33,488	(57,734)
Effect of exchange rate changes on cash and cash equivalents	17,167	(9,523)	9,274
Net increase (decrease) in cash and cash equivalents	1,168	27,299	(37,460)
Cash and cash equivalents at beginning of period	92,975	65,676	103,136
Cash and cash equivalents at end of period	$ 94,143	$ 92,975	$ 65,676