LONG-TERM DEBT AND OTHER FINANCING ARRANGEMENTS Credit Facility and Capital Lease Obligations(Details) Kč in Millions, in Millions		3 Months Ended
		Mar. 31, 2018 CZK (Kč)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 RON ( )	Dec. 31, 2017 USD ($)	Dec. 31, 2017 RON ( )
Line of Credit Facility [Line Items]
Unamortized Debt Issuance Expense			$ 5,765,000
Senior debt			1,047,600,000		$ 1,079,187,000
Credit facilities (1) – (3)			0		0
Capital leases			10,161,000		9,487,000
Total credit facilities and capital leases			10,161,000		9,487,000
Less: current maturities			(3,439,000)		(2,960,000)
Total non-current credit facilities and capital leases			6,722,000		6,527,000
Fair Value			$ 982,471,000		$ 1,016,077,000
2021 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[1],[2]	9.31%	9.31%	9.31%
Line of Credit Facility, Maximum Borrowing Capacity			$ 50,000,000
Senior Debt and Credit Facilities [Member]
Line of Credit Facility [Line Items]
Senior debt			1,047,600,000
Principal Amount of Liability Component			$ 1,053,365,000
CME NV and CME BV [Member]
Line of Credit Facility [Line Items]
Outstanding Shares Pledged, Percentage		100.00%	100.00%	100.00%
CME NV and CME BV [Member] | 2021 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding Shares Pledged, Percentage					100.00%	100.00%
BMG Bank Mendes Gans [Member]
Line of Credit Facility [Line Items]
Credit facilities (1) – (3)			$ 0
Line of credit facility cash pooling arrangement deposit			38,100,000		$ 12,400,000
Ceska Sporitelna [Member]
Line of Credit Facility [Line Items]
Receivables subject to a factoring agreement, recourse or non-recourse basis		Kč 575.0	27,900,000
Basis spread on variable rate (in percent)		0.95%
Receivables subject to a factoring agreement, non-recourse basis		Kč 127.2	6,200,000
Factoring Fee, Percentage		0.19%
Ceska Sporitelna [Member] | CET 21 [Member]
Line of Credit Facility [Line Items]
Credit facilities (1) – (3)			0
Global Funds IFN S.A. [Member]
Line of Credit Facility [Line Items]
Receivables subject to a factoring agreement, recourse or non-recourse basis			$ 36,000,000	136.1	$ 26,400,000	99.8
Basis spread on variable rate (in percent)		6.00%
Factoring Fee, Percentage		4.00%
Alternative Base Rate [Member] | 2021 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (in percent)		6.00%
Base Rate [Member] | 2021 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (in percent)		7.00%

[1] As at March 31, 2018, the 2021 Revolving Credit Facility was undrawn.

[2] Based on the three month LIBOR of 2.31% as at March 31, 2018.