LEASES - Supplemental balance sheet related to leases (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Operating Leases
Operating lease right-of-use assets	$ 135,078	$ 133,899
Current portion of operating lease liabilities	23,201	22,061
Long-term operating lease liabilities, less current portion	124,058	123,792
Total operating lease liabilities	147,259	145,853
Finance Leases
Property and equipment, at cost	7,488	7,499
Accumulated depreciation	(918)	(588)
Property and equipment, net	6,570	6,911
Current portion of long-term debt	413	390
Long-term debt, less current portion	7,181	7,390
Total finance lease liabilities	$ 7,594	$ 7,780
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtAndCapitalLeaseObligations	us-gaap:LongTermDebtAndCapitalLeaseObligations
Weighted Average Remaining Lease Term
Operating leases	7 years	7 years 1 month 6 days
Finance leases	10 years 6 months	10 years 10 months 24 days
Weighted Average Discount Rate
Operating leases	7.00%	7.00%
Finance leases	9.80%	9.70%