LEASE ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
ASSETS.
Operating lease assets	$ 106,735	$ 120,820
Operating Lease Assets Balance Sheet Location	Operating lease assets	Operating lease assets
Finance lease assets	$ 9,724	$ 12,659
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Total leased assets	$ 116,459	$ 133,479
Current
Operating Lease, Liability, Current	$ 42,891	$ 43,651
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Current	Operating Lease, Liability, Current
Finance Lease, Liability, Current	$ 4,676	$ 6,193
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Non-current
Operating Lease, Liability, Noncurrent	$ 83,146	$ 98,277
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating Lease, Liability, Noncurrent	Operating Lease, Liability, Noncurrent
Finance Lease, Liability, Noncurrent	$ 3,570	$ 4,763
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities, noncurrent	Other liabilities, noncurrent
Total lease liabilities	$ 134,283	$ 152,884