PENSION AND POSTRETIREMENT WELFARE PLANS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Net amount recognized in the consolidated balance sheet
Accrued pension cost at end of period	$ 3,142	$ 2,298
Pension Plan
Pension plan
Number of last years of employment in which the employee's compensation is considered for determining benefits	3 years
Change in projected benefit obligation:
Benefit obligation at beginning of period	5,738	6,277
Service cost	83	103
Employee contributions	12	10
Interest cost	266	241
Actuarial (gain) loss	1,131	(638)
Benefits paid	(280)	(255)
Benefit obligation at end of period	6,950	5,738
Change in plan assets:
Fair value of plan assets at beginning of period	4,847	4,086
Actual return on plan assets	273	691
Employee contributions	12	10
Employer contributions	243	315
Benefits and expenses paid	(280)	(255)
Fair value of plan assets at end of period	5,095	4,847
Net amount recognized in the consolidated balance sheet
Excess of projected benefit obligation over fair value of plan assets	1,855	891
Unrecognized loss	(2,028)	(875)
Accrued pension cost prior to pension adjustments	(173)	16
Accumulated Other Comprehensive Income at Current Measurement Date	2,028	875
Accrued pension cost at end of period	1,855	891
Accumulated benefit obligation	6,697	5,548
Amount of accumulated other comprehensive income expected to be recognized as a plan expense in next fiscal year	$ 190