PENSIONS AND OTHER BENEFITS - Components of net periodic cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Service cost
Interest cost on benefit obligation	$ 277	$ 255
Expected return on plan assets	(297)	$ (258)
Amortization of net gain (loss)	(1)
Net periodic benefit cost	$ (21)	$ (3)
Additional amount recognized due to settlement or curtailment
Total recognized in net periodic cost	$ (21)	$ (3)
Other changes in plan assets and benefit obligations recognized in other comprehensive loss (income):
Net actuarial loss (gain)	923	$ (1,635)
Amortization of net gain (loss)	1
Total recognized in other comprehensive loss (income)	924	$ (1,635)
Total recognized in net periodic cost and other comprehensive loss (income)	$ 903	$ (1,638)