LEASES AND RELATED PARTY LEASES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
ROU assets	$ 95,890	$ 94,530
Current lease liabilities	12,964	12,253
Non-current lease liabilities	100,328	97,504
Total lease liabilities	$ 113,292	$ 109,757
Leased facilities
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	12 years 6 months
Weighted average discount rate	5.20%
Leased vehicles
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	1 year 8 months 12 days
Weighted average discount rate	2.40%