LONG-TERM DEBT, DERIVATIVES AND LETTERS OF CREDIT - Additional Information (Details) € in Millions		3 Months Ended		9 Months Ended
	Jul. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 EUR (€)	Dec. 31, 2016 USD ($)	Feb. 29, 2016 USD ($)	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Borrowing capacity								$ 600,000,000
Commitment fee percentage				0.75%
Leverage Ratio on Credit Facility		8.34		8.34		8.34
Ratio of Senior Secured Debt To EBITDA		3.72		3.72		3.72
Interest Coverage Ratio		3.17		3.17		3.17
Minimum interest coverage ratio		3.00		3.00		3.00
Cash on hand		$ 26,681,000	$ 38,201,000	$ 26,681,000	$ 38,201,000		$ 46,216,000		$ 44,825,000
Available borrowing capacity		51,000,000		51,000,000
Write-off of deferred loan costs		1,244,000	$ 0	1,244,000	$ 0
Net Investment Hedge
Line of Credit Facility [Line Items]
Borrowing under credit facility		14,500,000		$ 14,500,000		€ 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		$ 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
Repayment of term loan	$ 160,000,000
Swing Line Facility
Line of Credit Facility [Line Items]
Borrowing capacity		35,000,000		$ 35,000,000
Standby Letters of Credit
Line of Credit Facility [Line Items]
Outstanding letters of credit		$ 22,600,000		$ 22,600,000			$ 21,600,000
March 31, 2018
Line of Credit Facility [Line Items]
Maximum Leverage Ratio		4.5		4.5		4.5
Maximum ratio of senior secured debt to consolidated EBITDA		3.75		3.75		3.75
June 30, 2018
Line of Credit Facility [Line Items]
Maximum Leverage Ratio		4.25		4.25		4.25
Maximum ratio of senior secured debt to consolidated EBITDA		3.25		3.25		3.25
September 30, 2018 and thereafter
Line of Credit Facility [Line Items]
Maximum Leverage Ratio		4.00		4.00		4.00
Maximum ratio of senior secured debt to consolidated EBITDA		3.00		3.00		3.00
September 30, 2017
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA		4.75		4.75		4.75
December 31, 2017
Line of Credit Facility [Line Items]
Maximum ratio of senior secured debt to consolidated EBITDA		4.25		4.25		4.25
Convertible debt
Line of Credit Facility [Line Items]
Debt term				72 months
Principal amount, long-term debt issued	$ 230,000,000
Interest rate on convertible debt	5.00%	5.00%		5.00%		5.00%
Unamortized issuance costs		$ 7,101,000		$ 7,101,000
Credit Facility
Line of Credit Facility [Line Items]
Write-off of deferred loan costs		1,200,000
Unamortized issuance costs		$ 2,400,000		$ 2,400,000