SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION CF (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			$ 28,038	$ 58,260
Capital expenditures	$ (80,803)	$ (79,212)	(101,866)	(146,989)
Proceeds from asset dispositions	329	6,806	11,819	16,107
Net cash provided by (used in) investing activities			(90,047)	(130,882)
Proceeds from borrowings			195,954	461,581
Debt issuance costs			(2,925)	0
Repayment of debt			(120,966)	(323,569)
Dividends paid			(4,910)	(23,746)
Increases (decreases) in cash related to intercompany advances and debt			0	0
Partial prepayment of put/call obligation			(25)	(28)
Acquisition of noncontrolling interest			0	(2,000)
Payment of contingent consideration			(10,000)	(8,000)
Tax benefit related to stock-based compensation			0	203
Net cash provided by financing activities			57,128	104,441
Effect of exchange rate changes on cash and cash equivalents			1,239	3,376
Net increase (decrease) in cash and cash equivalents			(3,642)	35,195
Cash and cash equivalents at beginning of period			104,310	104,146
Cash and cash equivalents at end of period	100,668	139,341	100,668	139,341
Consolidations, Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(631)	0
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
Debt issuance costs			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
Payment of contingent consideration			0	0
Tax benefit related to stock-based compensation				0
Net cash provided by financing activities			0	0
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			(631)	0
Cash and cash equivalents at beginning of period			0	0
Cash and cash equivalents at end of period	(631)	0	(631)	0
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(36,618)	(80,805)
Capital expenditures			(11,958)	(18,679)
Proceeds from asset dispositions			0	0
Net cash provided by (used in) investing activities			(11,958)	(18,679)
Proceeds from borrowings			191,501	461,575
Debt issuance costs			(2,925)
Repayment of debt			(116,051)	(316,200)
Dividends paid			(4,554)	(23,746)
Increases (decreases) in cash related to intercompany advances and debt			(54,611)	(2,366)
Partial prepayment of put/call obligation			(25)	(28)
Acquisition of noncontrolling interest				0
Payment of contingent consideration			0	0
Tax benefit related to stock-based compensation				203
Net cash provided by financing activities			13,335	119,438
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			(35,241)	19,954
Cash and cash equivalents at beginning of period			35,241	126
Cash and cash equivalents at end of period	0	20,080	0	20,080
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			56,788	96,181
Capital expenditures			(20,411)	(88,872)
Proceeds from asset dispositions			10,374	13,937
Net cash provided by (used in) investing activities			(10,037)	(74,935)
Proceeds from borrowings			0	0
Debt issuance costs			0
Repayment of debt			0	0
Dividends paid			4	0
Increases (decreases) in cash related to intercompany advances and debt			(49,136)	(20,977)
Partial prepayment of put/call obligation			0	0
Acquisition of noncontrolling interest				0
Payment of contingent consideration			0	0
Tax benefit related to stock-based compensation				0
Net cash provided by financing activities			(49,132)	(20,977)
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			(2,381)	269
Cash and cash equivalents at beginning of period			3,393	884
Cash and cash equivalents at end of period	1,012	1,153	1,012	1,153
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			8,499	42,884
Capital expenditures			(69,497)	(39,438)
Proceeds from asset dispositions			1,445	2,170
Net cash provided by (used in) investing activities			(68,052)	(37,268)
Proceeds from borrowings			4,453	6
Debt issuance costs			0
Repayment of debt			(4,915)	(7,369)
Dividends paid			(360)	0
Increases (decreases) in cash related to intercompany advances and debt			103,747	23,343
Partial prepayment of put/call obligation			0	0
Acquisition of noncontrolling interest				(2,000)
Payment of contingent consideration			(10,000)	(8,000)
Tax benefit related to stock-based compensation				0
Net cash provided by financing activities			92,925	5,980
Effect of exchange rate changes on cash and cash equivalents			1,239	3,376
Net increase (decrease) in cash and cash equivalents			34,611	14,972
Cash and cash equivalents at beginning of period			65,676	103,136
Cash and cash equivalents at end of period	$ 100,287	$ 118,108	$ 100,287	$ 118,108