RETIREMENT PLANS - Amounts in Consolidated Financials (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pension Plans
Amounts recognized on the consolidated balance sheets
Other Liabilities	$ 2,898	$ 3,894
Other Assets	3,435	3,105
Accumulated other comprehensive income, net of tax	2,953	1,418
Amounts recognized in accumulated other comprehensive loss
Net actuarial gain/(loss)	1,408	(386)
Accumulated other comprehensive income / ( loss), pre-tax	1,408	(386)
Accumulated other comprehensive income, net of tax	2,953	1,418
Postretirement Benefits
Amounts recognized on the consolidated balance sheets
Accrued and current liabilities	392	381
Other Liabilities	4,915	4,727
Accumulated other comprehensive income, net of tax	174	352
Amounts recognized in accumulated other comprehensive loss
Net actuarial gain/(loss)	174	352
Accumulated other comprehensive income / ( loss), pre-tax	174	352
Accumulated other comprehensive income, net of tax	$ 174	$ 352