STOCKHOLDERS' EQUITY - Changes to Accumulate Other Comprehensive Income by Components (Detail) - Gain (loss) on securities available-for-sale - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ (9,042)	$ (2,995)
Unrealized gain arising during the period	2,226	26,809
Reclassification adjustment from other comprehensive income	(3,356)	(16,789)
Tax effect of current period changes	470	(4,190)
Total changes, net of taxes	(660)	5,830
Balance at end of period	$ (9,702)	$ 2,835