OTHER COMPREHENSIVE LOSS - Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) - Reclassification out of Accumulated Other Comprehensive Income [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ (11,557)	$ (497)	$ 84
Reclassification from AOCI, Current Period, Tax	0	0	0
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	(11,557)	(497)	84
Realized gain (loss) on sales of debt securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	(13,198)	0	34
Provsion For Credit Losses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	1,641	0	0
Other Than Temporary Impairment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ 0	$ (497)	$ 50