NON-CONSOLIDATED VARIABLE INTEREST ENTITIES AND SERVICING ASSETS - Weighted-Averages of Key Economic Assumptions in Valuation Model (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Transfers and Servicing [Abstract]
Carrying amount of servicing assets	$ 33,071	$ 26,762	$ 27,428	$ 25,255
Fair value	$ 40,294	$ 31,027
Weighted-average expected life	7 years 10 months 9 days	8 years 4 months 20 days
Constant prepayment rate	6.73%	6.45%
Decrease in fair value due to 10% adverse change	$ 1,006	$ 748
Decrease in fair value due to 20% adverse change	$ 1,970	$ 1,464
Discount rate	11.20%	11.27%
Decrease in fair value due to 10% adverse change	$ 1,772	$ 1,450
Decrease in fair value due to 20% adverse change	$ 3,409	$ 2,783