LONG-TERM DEBT, DERIVATIVES AND LETTERS OF CREDIT - Additional Information (Details) € in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2018 EUR (€)	Dec. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Feb. 29, 2016 USD ($)
Line of Credit Facility [Line Items]
Borrowing capacity							$ 600,000,000
Commitment fee percentage	0.75%
Percentage of equity interests of material first-tier foreign subsidiaries guaranteed to the line of credit facility	65.00%	65.00%
Ratio of Senior Secured Debt To EBITDA	2.95	2.95
Interest Coverage Ratio	3.19	3.19
Cash on hand	$ 15,296,000		$ 26,552,000		$ 29,154,000	$ 46,216,000
Available borrowing capacity	80,000,000
Net Investment Hedge
Line of Credit Facility [Line Items]
Borrowing under credit facility	$ 14,400,000	€ 12.3
LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.75%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Borrowing capacity	$ 300,000,000						400,000,000
Debt term	5 years
Term Loan Facility
Line of Credit Facility [Line Items]
Borrowing capacity							$ 200,000,000
Debt term	5 years
Swing Line Facility
Line of Credit Facility [Line Items]
Borrowing capacity	$ 35,000,000
Standby Letters of Credit
Line of Credit Facility [Line Items]
Outstanding letters of credit	$ 21,800,000		$ 22,500,000
June 30, 2018
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	4.25	4.25
Minimum interest coverage ratio	2.25	2.25
September 30, 2018
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	3.50	3.50
Minimum interest coverage ratio	2.25	2.25
December 31, 2018
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	3.50	3.50
Minimum interest coverage ratio	2.25	2.25
March 31, 2019
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	3.50	3.50
June 30, 2019
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	3.50	3.50
September 30, 2019 and thereafter
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA	2.75	2.75
March 31, 2019 and thereafter
Line of Credit Facility [Line Items]
Minimum interest coverage ratio	2.50	2.50
Convertible debt
Line of Credit Facility [Line Items]
Principal amount, long-term debt issued				$ 230,000,000
Interest rate on convertible debt	5.00%	5.00%		5.00%
Credit Facility
Line of Credit Facility [Line Items]
Unamortized issuance costs	$ 2,400,000