SEGMENT INFORMATION Operating Performance and Assets by Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Income (Loss) from Equity Method Investments									$ 4,220	$ 4,877	$ (1,807)
Loss on disposal of assets									(17,595)	(14,499)	(30,693)
Operating income (loss)	$ (107,835)	$ (3,497)	$ (12,917)	$ (24,589)	$ (19,528)	$ (19,097)	$ (26,882)	$ (26,235)	(148,838)	(91,742)	(40,845)
Payments to Acquire Productive Assets									46,287	135,110	372,375
Depreciation and amortization									124,042	118,748	136,812
Assets	3,165,002				3,113,847				3,165,002	3,113,847
Equity Method Investments	119,884				203,876				119,884	203,876
Payments for Construction in Process									2,300	39,500	84,800
Restructuring and Related Cost, Accelerated Depreciation										10,400	28,700
Construction in Progress, Gross	67,710				199,275				67,710	199,275
Europe Caspian
Segment Reporting Information [Line Items]
Income (Loss) from Equity Method Investments									191	273	310
Operating Income Loss Including Income Loss From Unconsolidated Affiliates Excluding Gain Loss From Sale Of Property Plant And Equipment									22,774	13,840	50,406
Payments to Acquire Productive Assets									24,797	44,024	127,072
Depreciation and amortization									48,854	39,511	41,509
Assets	1,087,437				1,091,536				1,087,437	1,091,536
Equity Method Investments	270				257				270	257
Restructuring and Related Cost, Accelerated Depreciation										500	600
Africa
Segment Reporting Information [Line Items]
Operating Income Loss Including Income Loss From Unconsolidated Affiliates Excluding Gain Loss From Sale Of Property Plant And Equipment									32,326	30,179	19,702
Payments to Acquire Productive Assets									3,769	4,575	1,386
Depreciation and amortization									13,705	16,664	29,337
Assets	374,121				325,719				374,121	325,719
Restructuring and Related Cost, Accelerated Depreciation										6,000	16,800
Americas
Segment Reporting Information [Line Items]
Income (Loss) from Equity Method Investments									4,302	5,207	(2,117)
Operating Income Loss Including Income Loss From Unconsolidated Affiliates Excluding Gain Loss From Sale Of Property Plant And Equipment									(73,057)	4,224	34,463
Payments to Acquire Productive Assets									2,523	8,275	92,418
Depreciation and amortization									27,468	32,727	36,371
Assets	788,879				809,071				788,879	809,071
Equity Method Investments	116,276				200,362				116,276	200,362
Restructuring and Related Cost, Accelerated Depreciation										3,900	6,000
Asia Pacific
Segment Reporting Information [Line Items]
Operating Income Loss Including Income Loss From Unconsolidated Affiliates Excluding Gain Loss From Sale Of Property Plant And Equipment									(24,290)	(20,870)	4,073
Payments to Acquire Productive Assets									6,795	15,086	23,745
Depreciation and amortization									19,695	19,091	20,526
Assets	342,166				433,614				342,166	433,614
Restructuring and Related Cost, Accelerated Depreciation											5,300
Corporate and other
Segment Reporting Information [Line Items]
Income (Loss) from Equity Method Investments									(273)	(603)	0
Operating Income Loss Including Income Loss From Unconsolidated Affiliates Excluding Gain Loss From Sale Of Property Plant And Equipment									(88,996)	(104,616)	(118,796)
Payments to Acquire Productive Assets									8,403	63,150	127,754
Depreciation and amortization									14,320	10,755	$ 9,069
Assets	572,399				453,907				572,399	453,907
Equity Method Investments	$ 3,338				$ 3,257				$ 3,338	$ 3,257