ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (4,332)	$ (15,754)
Other comprehensive income before reclassification, net of tax			19,114	11,802
Reclassifications from accumulated other comprehensive income, net of tax			42	387
Total other comprehensive income	$ 8,480	$ 5,485	19,156	12,189
Ending Balance	14,824	(3,565)	14,824	(3,565)
Unrealized Gains (Losses) on Investments Available-for-Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			4,000	(6,630)
Other comprehensive income before reclassification, net of tax			19,114	11,802
Reclassifications from accumulated other comprehensive income, net of tax			(284)	(4)
Total other comprehensive income			18,830	11,798
Ending Balance	22,830	5,168	22,830	5,168
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(8,332)	(9,124)
Other comprehensive income before reclassification, net of tax			0	0
Reclassifications from accumulated other comprehensive income, net of tax			326	391
Total other comprehensive income			326	391
Ending Balance	$ (8,006)	$ (8,733)	$ (8,006)	$ (8,733)