LEASES - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease right-of-use assets	$ 138,525	$ 0
Current operating lease liability	21,835
Long-term operating lease liability	124,014	$ 0
Total operating lease liabilities	145,849
Property, plant, and equipment	15,561
Accumulated depreciation	(4,755)
Property, plant, and equipment, net	10,806
Current finance lease liability	761
Long-term finance lease liability	11,646
Total finance lease liabilities	$ 12,407
Operating Lease, Weighted Average Remaining Lease Term	8 years 3 months 11 days
Finance Lease, Weighted Average Remaining Lease Term	10 years 5 months 5 days
Operating Lease, Weighted Average Discount Rate, Percent	3.85%
Finance Lease, Weighted Average Discount Rate, Percent	4.05%