COMMITMENTS AND CONTINGENCIES - Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 12,827	$ 3,744
Operating cash flows from finance leases	125	0
Finance cash flows from finance leases	620	0
Non-cash investing and financing activities:
Right-of-use assets obtained in exchange for new operating lease liabilities	13,662	20,147
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 17,420	0
Accounting Standards Update 2016-02
Non-cash investing and financing activities:
Right-of-use assets obtained in exchange for new operating lease liabilities		$ 17,900