LEASES - Narrative (Details)	6 Months Ended
	Jun. 30, 2019 tranche
Lessee, Lease, Description [Line Items]
Number of tranches	4
Lessee, Operating Lease, Tranche One
Lessee, Lease, Description [Line Items]
Discount rate	3.45%
Lessee, Operating Lease, Tranche One | Minimum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	1 year
Lessee, Operating Lease, Tranche One | Maximum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	2 years
Lessee, Operating Lease, Tranche Two
Lessee, Lease, Description [Line Items]
Discount rate	4.04%
Lessee, Operating Lease, Tranche Two | Minimum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	3 years
Lessee, Operating Lease, Tranche Two | Maximum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	4 years
Lessee, Operating Lease, Tranche Three
Lessee, Lease, Description [Line Items]
Discount rate	4.38%
Lessee, Operating Lease, Tranche Three | Minimum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	5 years
Lessee, Operating Lease, Tranche Three | Maximum
Lessee, Lease, Description [Line Items]
Term of contract for operating leases	9 years
Lessee, Operating Lease, Tranche Four
Lessee, Lease, Description [Line Items]
Discount rate	5.10%
Term of contract for operating leases	10 years