SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION CF (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			$ 58,260	$ 101,167
Capital expenditures	$ (79,212)	$ (101,672)	(146,989)	(302,119)
Proceeds from asset dispositions	6,806	391,001	16,107	397,644
Net cash provided by (used in) investing activities			(130,882)	95,525
Proceeds from borrowings			461,581	219,354
Repayment of debt			(323,569)	(282,838)
Dividends paid			(23,746)	(22,689)
Increases (decreases) in cash related to intercompany advances and debt			0	0
Partial prepayment of put/call obligation			(28)	(30)
Acquisition of noncontrolling interest			(2,000)	(3,170)
Payment of contingent consideration			(8,000)	0
Repurchase of Common Stock		(23,300)	0	(43,423)
Issuance of Common Stock			0	1,398
Tax benefit related to stock-based compensation			203	1,642
Net cash provided by (used in) financing activities			104,441	(129,756)
Effect of exchange rate changes on cash and cash equivalents			3,376	(7,367)
Net increase (decrease) in cash and cash equivalents			35,195	59,569
Cash and cash equivalents at beginning of period			104,146	204,341
Cash and cash equivalents at end of period	139,341	263,910	139,341	263,910
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(80,805)	(45,192)
Capital expenditures			(18,679)	(25,668)
Proceeds from asset dispositions			0	0
Net cash provided by (used in) investing activities			(18,679)	(25,668)
Proceeds from borrowings			461,575	218,000
Repayment of debt			(316,200)	(275,502)
Dividends paid			(23,746)	(22,689)
Increases (decreases) in cash related to intercompany advances and debt			(2,366)	241,300
Partial prepayment of put/call obligation			(28)	(30)
Acquisition of noncontrolling interest			0	0
Payment of contingent consideration			0
Repurchase of Common Stock				(43,423)
Issuance of Common Stock				1,398
Tax benefit related to stock-based compensation			203	1,642
Net cash provided by (used in) financing activities			119,438	120,696
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			19,954	49,836
Cash and cash equivalents at beginning of period			126	4,640
Cash and cash equivalents at end of period	20,080	54,476	20,080	54,476
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			96,181	115,666
Capital expenditures			(88,872)	(141,269)
Proceeds from asset dispositions			13,937	208,373
Net cash provided by (used in) investing activities			(74,935)	67,104
Proceeds from borrowings			0	0
Repayment of debt			0	0
Dividends paid			0	0
Increases (decreases) in cash related to intercompany advances and debt			(20,977)	(169,002)
Partial prepayment of put/call obligation			0	0
Acquisition of noncontrolling interest			0	0
Payment of contingent consideration			0
Repurchase of Common Stock				0
Issuance of Common Stock				0
Tax benefit related to stock-based compensation			0	0
Net cash provided by (used in) financing activities			(20,977)	(169,002)
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			269	13,768
Cash and cash equivalents at beginning of period			884	0
Cash and cash equivalents at end of period	1,153	13,768	1,153	13,768
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			42,884	30,247
Capital expenditures			(39,438)	(135,182)
Proceeds from asset dispositions			2,170	189,271
Net cash provided by (used in) investing activities			(37,268)	54,089
Proceeds from borrowings			6	1,354
Repayment of debt			(7,369)	(7,336)
Dividends paid			0	0
Increases (decreases) in cash related to intercompany advances and debt			23,343	(72,298)
Partial prepayment of put/call obligation			0	0
Acquisition of noncontrolling interest			(2,000)	(3,170)
Payment of contingent consideration			(8,000)
Repurchase of Common Stock				0
Issuance of Common Stock				0
Tax benefit related to stock-based compensation			0	0
Net cash provided by (used in) financing activities			5,980	(81,450)
Effect of exchange rate changes on cash and cash equivalents			3,376	(7,367)
Net increase (decrease) in cash and cash equivalents			14,972	(4,481)
Cash and cash equivalents at beginning of period			103,136	200,147
Cash and cash equivalents at end of period	118,108	195,666	118,108	195,666
Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			0	446
Capital expenditures			0	0
Proceeds from asset dispositions			0	0
Net cash provided by (used in) investing activities			0	0
Proceeds from borrowings			0	0
Repayment of debt			0	0
Dividends paid			0	0
Increases (decreases) in cash related to intercompany advances and debt			0	0
Partial prepayment of put/call obligation			0	0
Acquisition of noncontrolling interest			0	0
Payment of contingent consideration			0
Repurchase of Common Stock				0
Issuance of Common Stock				0
Tax benefit related to stock-based compensation			0	0
Net cash provided by (used in) financing activities			0	0
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			0	446
Cash and cash equivalents at beginning of period			0	(446)
Cash and cash equivalents at end of period	$ 0	$ 0	$ 0	$ 0