LONG-TERM DEBT, LETTERS OF CREDIT AND DERIVATIVES - Additional Information (Details) € in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 EUR (€)	Aug. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jul. 31, 2017 USD ($)
Line of Credit Facility [Line Items]
Borrowing capacity			$ 275,000,000.0
Additional borrowing capacity (up to)			100,000,000
Commitment fee percentage	0.55%
Percentage of equity interests of material first-tier foreign subsidiaries guaranteed to the line of credit facility	65.00%	65.00%
Senior Secured Leverage Ratio	2.00	2.00
Debt Service Coverage Ratio	1.97	1.97
Net Leverage Ratio	5.00	5.00
Cash on hand	$ 10,268,000			$ 18,288,000
Available borrowing capacity	59,000,000
Net Investment Hedge
Line of Credit Facility [Line Items]
Borrowing under credit facility	$ 13,400,000	€ 12.3
LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.50%
Credit Facility revolver
Line of Credit Facility [Line Items]
Borrowing capacity			225,000,000.0
Swing Line Facility
Line of Credit Facility [Line Items]
Borrowing capacity			35,000,000.0
Standby Letters of Credit
Line of Credit Facility [Line Items]
Outstanding letters of credit	$ 18,500,000			$ 22,800,000
Credit Facility term loan
Line of Credit Facility [Line Items]
Borrowing capacity			$ 50,000,000.0
Total Credit Facility
Line of Credit Facility [Line Items]
Unamortized issuance costs	$ 2,400,000
Convertible debt
Line of Credit Facility [Line Items]
Principal amount, long-term debt issued					$ 230,000,000.0
September 30, 2019
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.75	2.75
Minimum Debt Service Coverage Ratio	1.10	1.10
December 31, 2019
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.75	2.75
Minimum Debt Service Coverage Ratio	1.25	1.25
March 31, 2020
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.75	2.75
Maximum Net Leverage Ratio	5.50	5.50
Minimum Debt Service Coverage Ratio	1.25	1.25
June 30, 2020
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.75	2.75
Maximum Net Leverage Ratio	5.25	5.25
Minimum Debt Service Coverage Ratio	1.25	1.25
September 30, 2020
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.75	2.75
Maximum Net Leverage Ratio	5.00	5.00
Minimum Debt Service Coverage Ratio	1.25	1.25
December 31, 2020 and thereafter
Line of Credit Facility [Line Items]
Maximum Senior Secured Leverage Ratio	2.50	2.50
Maximum Net Leverage Ratio	4.50	4.50
Minimum Debt Service Coverage Ratio	1.50	1.50