INDEBTEDNESS - Narrative (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Long-term debt
Borrowings under line of credit	$ 237.5	$ 198.5
U.S. term loans
Long-term debt
Loan facility quarterly installment rate	5.00%
Credit Agreement | Credit Facility | Base rate
Long-term debt
Borrowings under line of credit			$ 10.0
Basis spread on variable rate			5.25%
Credit Agreement | Credit Facility | LIBOR
Long-term debt
Borrowings under line of credit	$ 180.0		$ 128.5
Basis spread on variable rate	1.91%		3.27%
Credit Agreement | Letter of Credit
Long-term debt
Interest rate	1.75%		1.50%
Amended Credit Agreement | U.S. term loans
Long-term debt
Interest rate	1.93%		3.30%
Amended Credit Agreement | Multi-currency term loans
Long-term debt
Interest rate	1.75%		1.50%