OTHER COMPREHENSIVE INCOME (LOSS)-AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance, January 1	$ (14,529)	$ (13,969)
Change in other comprehensive income before reclassification	219	(1,023)
Amounts reclassified from accumulated other comprehensive income	4,909	463
Net current period other comprehensive income (loss)	5,128	(560)
Ending balance, December 31	(9,401)	(14,529)
Unrealized Gains and Losses on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance, January 1	10,278	(3,635)
Change in other comprehensive income before reclassification	(1,214)	13,911
Amounts reclassified from accumulated other comprehensive income	(11)	2
Net current period other comprehensive income (loss)	(1,225)	13,913
Ending balance, December 31	9,053	10,278
Retirement Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance, January 1	(24,807)	(10,334)
Change in other comprehensive income before reclassification	1,433	(14,934)
Amounts reclassified from accumulated other comprehensive income	4,920	461
Net current period other comprehensive income (loss)	6,353	(14,473)
Ending balance, December 31	$ (18,454)	$ (24,807)