ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (6,857)	$ (6,614)
Other comprehensive income before reclassification, net of tax	(9,368)	904
Reclassifications from accumulated other comprehensive income, net of tax	84	176
Current period change in other comprehensive income, net of tax	(9,284)	1,080
Reclassfication of tax effects from accumulated other comprehensive income	(1,477)
Ending Balance	(17,618)	(5,534)
Unrealized Gains (Losses) on Investments Available-for-Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	687	1,642
Other comprehensive income before reclassification, net of tax	(9,368)	904
Reclassifications from accumulated other comprehensive income, net of tax	(47)	(2)
Current period change in other comprehensive income, net of tax	(9,415)	902
Reclassfication of tax effects from accumulated other comprehensive income	148
Ending Balance	(8,580)	2,544
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7,544)	(8,256)
Other comprehensive income before reclassification, net of tax	0	0
Reclassifications from accumulated other comprehensive income, net of tax	131	178
Current period change in other comprehensive income, net of tax	131	178
Reclassfication of tax effects from accumulated other comprehensive income	(1,625)
Ending Balance	$ (9,038)	$ (8,078)