LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Credit Facility (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Arrangements
Borrowings under credit facilities			$ 180,000
Repayment of debt			326,098	$ 58,938	$ 71,260
Credit Facility
Financing Arrangements
Maximum borrowing capacity			250,000
Additional borrowing capacity that may be requested			125,000
Borrowings under credit facilities	$ 180,000
Repayment of debt		$ 180,000
Remaining borrowing capacity			180,000
Swing Line Facility
Financing Arrangements
Maximum borrowing capacity			25,000
Letters of Credit, Sub-Facility
Financing Arrangements
Maximum borrowing capacity			$ 20,000