LEASE COMMITMENTS - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Operating Leases
Operating lease right-of-use assets	$ 72,377	$ 83,222
Operating lease liability, current	$ 16,578
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accounts Payable, Accrued Liabilities, and Derivative Liabilities, Current
Operating lease liabilities	$ 55,276	$ 61,331
Total operating lease liabilities	71,854
Finance Leases
Finance leases included in property, plant and equipment, gross	47,020
Accumulated depreciation of finance leases included in property, plant and equipment, net	(4,271)
Total finance leases	$ 42,749
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant and Equipment, Net
Current portion of finance lease liabilities	$ 4,318
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Long-term Debt and Capital Lease Obligations, Current
Noncurrent portion of finance lease liabilities	$ 25,634
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term Debt and Capital Lease Obligations
Total finance lease liabilities	$ 29,952
Weighted Average Remaining Lease Term (in years)
Operating leases	6 years 1 month 6 days
Finance leases	7 years
Weighted Average Discount Rate
Operating leases	5.05%
Finance leases	5.13%