LONG-TERM DEBT AND LINES OF CREDIT - Derivative Instruments (Details) - Interest rate swap - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Prepaid expenses and other current assets
Debt Instrument [Line Items]
Interest rate swaps	$ 0	$ 472
Notional amount		250,000
Accounts payable and accrued liabilities
Debt Instrument [Line Items]
Weighted-average fixed rate of interest (as a percent)	1.65%
Interest rate swaps	$ 4,244	0
Notional amount	$ 550,000
Other noncurrent liabilities
Debt Instrument [Line Items]
Weighted-average fixed rate of interest (as a percent)	2.73%
Interest rate swaps	$ 82,479	45,604
Notional amount	$ 1,250,000	$ 1,550,000