PENSIONS AND OTHER BENEFITS - Transition from providing retirement benefits under defined pension plan to defined contribution 401(K) plan (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2014 USD ($)
Change in projected benefit obligation
Service cost
Interest cost	277
Transition from defined pension plan to defined contribution 401(k) plan
Change in projected benefit obligation
Benefit obligation at beginning of year	5,250
Actuarial gain	(977)
Service cost
Interest cost	277
Curtailments and settlements
Benefits paid	(4,550)
Benefit obligation at end of year
Change in plan assets
Plan assets at estimated fair value at beginning of year	6,868
Actual return on plan assets	(2,318)
Contributions by employer
Curtailments and settlements
Benefits paid	(4,550)
Fair value of plan assets at end of year
Funded status and recognized asset included in other assets on the balance sheet