SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION CF (Details) (USD $) In Thousands, unless otherwise specified	2 Months Ended		12 Months Ended
	Mar. 31, 2014	Jan. 31, 2014	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			$ 232,094	$ 266,764	$ 231,347
Capital expenditures			(628,613)	(571,425)	(326,420)
Deposits on assets held for sale			0	0	200
Acquisitions, net of cash received			(39,850)	0	0
Proceeds from sales of joint ventures			(112,210)	0	0
Proceeds from asset dispositions			289,951	314,847	239,843
Investment in unconsolidated affiliate			0	(51,179)	(2,378)
Net cash used in investing activities			(266,302)	(307,757)	(88,755)
Proceeds from borrowings			533,064	675,449	159,993
Payments for contingent consideration			(6,000)	0	0
Debt issuance costs			(15,523)	(10,344)	(871)
Repayment of debt and debt redemption premiums			(512,492)	(663,921)	(113,419)
Proceeds from assignment of aircraft purchase agreements			106,113	0	0
Dividends paid			(36,320)	(28,734)	(21,616)
Increases (decreases) in cash related to intercompany advances and debt			0	0	0
Partial prepayment of put/call obligation			(57)	(63)	(63)
Acquisition of noncontrolling interest			(2,078)	0	(262)
Repurchase of common stock	(44,200)	(33,500)	(77,661)	(1,219)	(25,085)
Issuance of Common Stock			15,398	15,289	5,293
Tax benefit related to stock-based compensation			5,723	500	354
Net cash provided by (used in) financing activities			10,167	(13,043)	4,324
Effect of exchange rate changes on Cash and Cash Equivalents			12,759	8,109	(1,727)
Net increase (decrease) in cash and cash equivalents			(11,282)	(45,927)	145,189
Cash and cash equivalents at beginning of period			215,623	261,550	116,361
Cash and cash equivalents at end of period	204,341		204,341	215,623	261,550
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(48,173)	(45,184)	(31,226)
Capital expenditures			(33,197)	(17,532)	(2,710)
Deposits on assets held for sale					0
Acquisitions, net of cash received			0
Proceeds from sales of joint ventures			0
Proceeds from asset dispositions			0	0	0
Investment in unconsolidated affiliate				0	(2,378)
Net cash used in investing activities			(33,197)	(17,532)	(5,088)
Proceeds from borrowings			528,600	675,000	159,300
Payments for contingent consideration			0
Debt issuance costs			(15,523)	(10,344)	(871)
Repayment of debt and debt redemption premiums			(508,060)	(663,921)	(95,290)
Proceeds from assignment of aircraft purchase agreements			0
Dividends paid			(33,254)	(11,242)	29,781
Increases (decreases) in cash related to intercompany advances and debt			138,991	13,960	15,429
Partial prepayment of put/call obligation			(57)	(63)	(63)
Acquisition of noncontrolling interest			0		0
Repurchase of common stock			(77,661)	(1,219)	(25,085)
Issuance of Common Stock			15,398	15,289	5,293
Tax benefit related to stock-based compensation			5,723	500	354
Net cash provided by (used in) financing activities			54,157	17,960	88,848
Effect of exchange rate changes on Cash and Cash Equivalents			0	0	0
Net increase (decrease) in cash and cash equivalents			(27,213)	(44,756)	52,534
Cash and cash equivalents at beginning of period			31,853	76,609	24,075
Cash and cash equivalents at end of period	4,640		4,640	31,853	76,609
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			107,059	156,371	91,773
Capital expenditures			(482,786)	(503,120)	(230,858)
Deposits on assets held for sale					0
Acquisitions, net of cash received			0
Proceeds from sales of joint ventures			0
Proceeds from asset dispositions			284,042	185,876	173,603
Investment in unconsolidated affiliate				0	0
Net cash used in investing activities			(198,744)	(317,244)	(57,255)
Proceeds from borrowings			0	0	0
Payments for contingent consideration			0
Debt issuance costs			0	0	0
Repayment of debt and debt redemption premiums			0	0	0
Proceeds from assignment of aircraft purchase agreements			106,113
Dividends paid			34	(12,955)	(24,927)
Increases (decreases) in cash related to intercompany advances and debt			(19,832)	176,043	(11,407)
Partial prepayment of put/call obligation			0	0	0
Acquisition of noncontrolling interest			0		(262)
Repurchase of common stock			0	0	0
Issuance of Common Stock			0	0	0
Tax benefit related to stock-based compensation			0	0	0
Net cash provided by (used in) financing activities			86,315	163,088	(36,596)
Effect of exchange rate changes on Cash and Cash Equivalents			0	0	0
Net increase (decrease) in cash and cash equivalents			(5,370)	2,215	(2,078)
Cash and cash equivalents at beginning of period			5,370	3,155	5,233
Cash and cash equivalents at end of period	0		0	5,370	3,155
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			173,654	155,577	170,800
Capital expenditures			(246,868)	(202,633)	(92,852)
Deposits on assets held for sale					200
Acquisitions, net of cash received			(39,850)
Proceeds from sales of joint ventures			(112,210)
Proceeds from asset dispositions			140,147	280,831	66,240
Investment in unconsolidated affiliate				(51,179)	0
Net cash used in investing activities			(34,361)	27,019	(26,412)
Proceeds from borrowings			4,464	449	693
Payments for contingent consideration			(6,000)
Debt issuance costs			0	0	0
Repayment of debt and debt redemption premiums			(4,432)	0	(18,129)
Proceeds from assignment of aircraft purchase agreements			0
Dividends paid			(3,100)	(4,537)	(26,470)
Increases (decreases) in cash related to intercompany advances and debt			(119,159)	(190,003)	(4,022)
Partial prepayment of put/call obligation			0	0	0
Acquisition of noncontrolling interest			(2,078)		0
Repurchase of common stock			0	0	0
Issuance of Common Stock			0	0	0
Tax benefit related to stock-based compensation			0	0	0
Net cash provided by (used in) financing activities			(130,305)	(194,091)	(47,928)
Effect of exchange rate changes on Cash and Cash Equivalents			12,759	8,109	(1,727)
Net increase (decrease) in cash and cash equivalents			21,747	(3,386)	94,733
Cash and cash equivalents at beginning of period			178,400	181,786	87,053
Cash and cash equivalents at end of period	200,147		200,147	178,400	181,786
Consolidations, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(446)	0	0
Capital expenditures			134,238	151,860	0
Deposits on assets held for sale					0
Acquisitions, net of cash received			0
Proceeds from sales of joint ventures			0
Proceeds from asset dispositions			(134,238)	(151,860)	0
Investment in unconsolidated affiliate				0	0
Net cash used in investing activities			0	0	0
Proceeds from borrowings			0	0	0
Payments for contingent consideration			0
Debt issuance costs			0	0	0
Repayment of debt and debt redemption premiums			0	0	0
Proceeds from assignment of aircraft purchase agreements			0
Dividends paid			0	0	0
Increases (decreases) in cash related to intercompany advances and debt			0	0	0
Partial prepayment of put/call obligation			0	0	0
Acquisition of noncontrolling interest			0		0
Repurchase of common stock			0	0	0
Issuance of Common Stock			0	0	0
Tax benefit related to stock-based compensation			0		0
Net cash provided by (used in) 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			(446)	0	0
Cash and cash equivalents at beginning of period			0	0	0
Cash and cash equivalents at end of period	$ (446)		$ (446)	$ 0	$ 0