LEASES - Amounts Recognized in the Balance Sheet for Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases:
Operating lease right-of-use assets	$ 64,605	$ 66,555
Current portion of operating lease obligations	17,036	17,770
Operating lease obligations (non-current)	52,235	$ 54,477
Finance Leases:
Property, plant and equipment, net	5,226		$ 5,200
Current portion of long-term debt and finance lease obligations	283
Long-term debt and finance lease obligations	$ 5,106
Weighted average remaining lease term, operating leases	6 years
Weighted average remaining lease term, finance leases	14 years
Weighted average discount rate, operating leases	8.40%
Weighted average discount rate, finance leases	6.30%