ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Net Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (6,614)	$ (1,297)	$ (823)
Total other comprehensive income	(243)	(5,317)	(474)
Ending Balance	(6,857)	(6,614)	(1,297)
Unrealized Gains (Losses) on Investments Available-for-Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	1,642	6,566	8,078
Total other comprehensive income	(955)	(4,924)	(1,512)
Ending Balance	687	1,642	6,566
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(8,256)	(7,863)	(8,901)
Total other comprehensive income	712	(393)	1,038
Ending Balance	$ (7,544)	$ (8,256)	$ (7,863)