SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash Flows (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents
Cash and cash equivalents	$ 294,873	$ 120,685	$ 65,641	$ 90,058
Restricted cash	12,383	8,677	9,138	20,821
Pledged cash and cash equivalents (NOTE 9)	21,324	7,204	5,361	9,469
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	$ 328,580	$ 136,566	$ 80,140	$ 120,348