LEASE ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS.
Operating lease assets	$ 112,129	$ 120,820
Operating Lease Assets Balance Sheet Location	Operating lease assets	Operating lease assets
Finance lease assets	$ 10,947	$ 12,659
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Total leased assets	$ 123,076	$ 133,479
Current
Operating Lease, Liability, Current	$ 43,043	$ 43,651
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Current	Operating Lease, Liability, Current
Finance Lease, Liability, Current	$ 5,558	$ 6,193
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Non-current
Operating Lease, Liability, Noncurrent	$ 89,967	$ 98,277
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Noncurrent	Operating Lease, Liability, Noncurrent
Finance Lease, Liability, Noncurrent	$ 3,766	$ 4,763
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities, noncurrent	Other liabilities, noncurrent
Total lease liabilities	$ 142,334	$ 152,884