LEASE ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS.
Operating lease assets	$ 120,820	$ 150,808
Operating Lease Assets Balance Sheet Location	us-gaap:OperatingLeaseRightOfUseAsset	us-gaap:OperatingLeaseRightOfUseAsset
Finance lease assets	$ 12,659	$ 18,016
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Total leased assets	$ 133,479	$ 168,824
Current
Operating Lease, Liability, Current	$ 43,651	$ 45,218
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Current	Operating Lease, Liability, Current
Finance Lease, Liability, Current	$ 6,193	$ 7,470
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Non-current
Operating Lease, Liability, Noncurrent	$ 98,277	$ 127,395
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Noncurrent	Operating Lease, Liability, Noncurrent
Finance Lease, Liability, Noncurrent	$ 4,763	$ 8,896
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities, noncurrent	Other liabilities, noncurrent
Total lease liabilities	$ 152,884	$ 188,979