LEASES AND RELATED PARTY LEASES - Supplemental Balance Sheet Information (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
ROU assets	$ 64,999
Current lease liabilities	12,619
Non-current lease liabilities	61,711
Total lease liabilities	$ 74,330
Leased facilities
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	9 years 11 months 5 days
Weighted average discount rate	5.70%
Leased vehicles
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	3 years 4 months 20 days
Weighted average discount rate	3.20%