STOCKHOLDERS' EQUITY - Changes to Accumulated Other Comprehensive (Loss) Income by Components (Detail) - Gain (loss) on securities available-for-sale - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ (54,148)	$ (18,091)	$ (11,900)	$ (24,117)
Unrealized gain (loss) arising during the period	56,701	7,678	(3,182)	16,422
Reclassification adjustment from other comprehensive income	(2,011)	0	(2,011)	(208)
Tax effect of current period changes	(16,107)	(2,255)	1,528	(4,765)
Total changes, net of taxes	38,583	5,423	(3,665)	11,449
Balance at end of period	$ (15,565)	$ (12,668)	$ (15,565)	$ (12,668)