ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (15,754)	$ (6,857)
Other comprehensive income before reclassification, net of tax			12,475	(16,479)
Reclassifications from accumulated other comprehensive income, net of tax			571	393
Total other comprehensive income	$ 857	$ (3,864)	13,046	(16,086)
Reclassfication of tax effects from accumulated other comprehensive income				(1,477)
Ending Balance	(2,708)	(24,420)	(2,708)	(24,420)
Unrealized Gains (Losses) on Investments Available-for-Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(6,630)	687
Other comprehensive income before reclassification, net of tax			12,475	(16,479)
Reclassifications from accumulated other comprehensive income, net of tax			(15)	(107)
Total other comprehensive income			12,460	(16,586)
Reclassfication of tax effects from accumulated other comprehensive income				148
Ending Balance	5,830	(15,751)	5,830	(15,751)
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(9,124)	(7,544)
Other comprehensive income before reclassification, net of tax			0	0
Reclassifications from accumulated other comprehensive income, net of tax			586	500
Total other comprehensive income			586	500
Reclassfication of tax effects from accumulated other comprehensive income				(1,625)
Ending Balance	$ (8,538)	$ (8,669)	$ (8,538)	$ (8,669)