PENSION PLAN - Plan Asset Allocations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	100.00%	100.00%
Net transition obligation (asset), prior service cost (credit), and estimated net loss (gain) for the plan that are expected to be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year
Estimated net loss (gain) for the plan expected to be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year	$ 257
Cash
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	9.00%	7.00%
Fixed income
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	27.00%	28.00%
Alternative investments
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	15.00%	12.00%
Domestic equities
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	32.00%	33.00%
Foreign equities
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	16.00%	17.00%
Real estate inv. Trusts (REITs)
Pension plan asset allocations as well as target allocations for 2014
Total (as a percent)	1.00%	3.00%