LEASES - Maturities of operating lease liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Operating Lease Liabilities, Payments Due [Abstract]
One year	$ 11,023
Two years	10,563
Three years	10,002
Four years	10,090
Five years	9,494
Thereafter	46,671
Total undiscounted lease payments	97,843
Less: Present value discount	(17,228)
Lease Liability	$ 80,615	$ 85,100