EMPLOYEE BENEFITS (Investments of the Plan and Funded Status) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets
Projected benefit obligation	$ 41,078	$ 46,017
Accumulated benefit obligation	41,078	46,017
Fair value of plan assets	31,349	27,791
Pension Plans
Defined Benefit Plan Disclosure
Pension plan portfolio assets designed to avoid losses of this percentage in a single year(as a percent)	20.00%
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets
Excess of benefit obligation over plan assets	(9,728)	(18,225)
Unrecognized actuarial loss	18,025	24,811
Net amount recognized	8,297	6,586
Amounts recognized in the balance sheet consist of:
Accrued benefit liability—current	(133)	0
Accrued benefit liability—noncurrent	(9,595)	(18,225)
Accumulated other comprehensive income—net actuarial loss	18,025	24,811
Net amount recognized	8,297	6,586
Forest Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	100.00%	100.00%
Wiser Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	100.00%	100.00%
Postretirement Benefits Plan
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets
Excess of benefit obligation over plan assets	(15,436)	(17,227)
Unrecognized actuarial loss	2,303	5,633
Net amount recognized	(13,133)	(11,594)
Amounts recognized in the balance sheet consist of:
Accrued benefit liability—current	(641)	0
Accrued benefit liability—noncurrent	(14,795)	(17,227)
Accumulated other comprehensive income—net actuarial loss	2,303	5,633
Net amount recognized	$ (13,133)	$ (11,594)
Fixed income securities | Forest Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	22.00%	24.00%
Fixed income securities | Wiser Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	21.00%	25.00%
Equity securities | Pension Plans
Defined Benefit Plan Disclosure
Pension plans target allocation in equity, maximum (as a percent)	75.00%
Equity securities | Forest Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	77.00%	75.00%
Equity securities | Wiser Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	78.00%	74.00%
Other | Forest Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	1.00%	1.00%
Other | Wiser Pension Plan
Defined Benefit Plan, Assets, Target Allocations
Weighted average asset allocations of pension plans (as a percent)	1.00%	1.00%