FAIR VALUES OF FINANCIAL INSTRUMENTS - Gains and (Losses) on Non-Recurring Assets (Detail) - Nonrecurring - Impaired loans - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Single family residential mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses recognized on assets measured at fair value	$ (191)	$ 0	$ (722)	$ (490)
Commercial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses recognized on assets measured at fair value	(3,106)	0	(11,620)	0
SBA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses recognized on assets measured at fair value	(1,534)	0	(3,078)	(46)
Other consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses recognized on assets measured at fair value	$ 0	$ 0	$ (4)	$ (88)