LEASES - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 4,061	$ 8,000	$ 11,095	$ 14,000
Operating lease liabilities	133,257		133,257		$ 144,000	$ 0
Alpharetta, Georgia
Lessee, Lease, Description [Line Items]
Operating lease liabilities	$ 40,000		$ 40,000
Term of contract	15 years		15 years