ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (15,754)	$ (6,857)
Other comprehensive income before reclassification, net of tax			11,802	(12,491)
Reclassifications from accumulated other comprehensive income, net of tax			387	269
Current period change in other comprehensive income, net of tax	$ 5,485	$ (2,938)	12,189	(12,222)
Reclassfication of tax effects from accumulated other comprehensive income				(1,477)
Ending Balance	(3,565)	(20,556)	(3,565)	(20,556)
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			11,802	(12,491)
Reclassifications from accumulated other comprehensive income, net of tax			(4)	(47)
Current period change in other comprehensive income, net of tax			11,798	(12,538)
Reclassfication of tax effects from accumulated other comprehensive income				148
Ending Balance	5,168	(11,703)	5,168	(11,703)
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			391	316
Current period change in other comprehensive income, net of tax			391	316
Reclassfication of tax effects from accumulated other comprehensive income				(1,625)
Ending Balance	$ (8,733)	$ (8,853)	$ (8,733)	$ (8,853)