ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (6,857)	$ (6,614)
Other comprehensive income before reclassification, net of tax			(12,491)	3,314
Reclassifications from accumulated other comprehensive income, net of tax			269	(412)
Current period change in other comprehensive income, net of tax	$ (2,938)	$ 1,822	(12,222)	2,902
Reclassfication of tax effects from accumulated other comprehensive income			(1,477)
Ending Balance	(20,556)	(3,712)	(20,556)	(3,712)
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			(12,491)	3,314
Reclassifications from accumulated other comprehensive income, net of tax			(47)	(767)
Current period change in other comprehensive income, net of tax			(12,538)	2,547
Reclassfication of tax effects from accumulated other comprehensive income			148
Ending Balance	(11,703)	4,189	(11,703)	4,189
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			316	355
Current period change in other comprehensive income, net of tax			316	355
Reclassfication of tax effects from accumulated other comprehensive income			(1,625)
Ending Balance	$ (8,853)	$ (7,901)	$ (8,853)	$ (7,901)