LEASES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Assets
Operating lease right-of-use assets	$ 59,949	$ 55,188	$ 55,188
Liabilities
Short-term operating lease liabilities	17,590	15,891	15,891
Long-term operating lease liabilities	41,267	$ 38,010	38,010
Total operating lease liabilities	$ 58,857		$ 53,901