PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Weighted-average asset allocations
Weighted-average asset allocations (as a percent)		100.00%	100.00%
Temporary investment funds
Weighted-average asset allocations
Weighted-average asset allocations (as a percent)		3.00%	4.00%
Equity investment funds
Weighted-average asset allocations
Weighted-average asset allocations (as a percent)		61.00%	59.00%
Target allocation
Target allocation percentage		60.00%
Fixed income Funds
Weighted-average asset allocations
Weighted-average asset allocations (as a percent)		36.00%	37.00%
Target allocation
Target allocation percentage		40.00%
Pension Benefits
Amounts recognized in the consolidated balance sheet consist of:
Current liabilities		$ (20,645,000)	$ (16,875,000)
Noncurrent liabilities		(64,382,000)	(56,336,000)
Net amount recognized		(85,027,000)	(73,211,000)
Amounts recognized in accumulated other comprehensive income before taxes:
Net actuarial loss		79,996,000	61,918,000
Prior service cost (benefit)		25,000	39,000
Net amount recognized		80,021,000	61,957,000
Total amount recognized in OCI
Net actuarial (gain)/loss		22,187,000	29,546,000
Amortization of:
Prior service cost/(credit)		(14,000)	(101,000)
Actuarial (gain)/loss		(4,108,000)	(1,996,000)
Total recognized in OCI		18,065,000	27,449,000
Amount included in accumulated other comprehensive income and expected to be recognized in net periodic pension cost in next fiscal year
Estimated net actuarial loss	8,623,000
Estimated prior service costs	14,000
Components of the net periodic benefit cost
Service cost		7,209,000	10,634,000	10,401,000
Interest cost		11,819,000	11,211,000	10,811,000
Expected return on plan assets		(12,523,000)	(13,008,000)	(11,671,000)
Amortization of prior service cost		14,000	32,000	61,000
Recognized actuarial loss		4,108,000	1,996,000	1,058,000
Curtailment (benefits) expense			69,000
Net periodic benefit cost		10,627,000	10,934,000	10,660,000
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)				6.10%
Expected return on plan assets (as a percent)		7.10%	8.20%	8.15%
Rate of compensation increase (as a percent)		2.50%	2.50%	4.00%
Estimated future benefit payments
Expected contributions in next fiscal year		20,600,000
2013		6,124,000
2014		7,134,000
2015		8,252,000
2016		9,439,000
2017		10,747,000
2018-2022		76,037,000
Pension Benefits | Maximum
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)		5.15%	5.75%
Pension Benefits | Minimum
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)		5.10%	4.95%
Other Benefits
Amounts recognized in the consolidated balance sheet consist of:
Current liabilities		(1,141,000)	(1,229,000)
Noncurrent liabilities		(10,005,000)	(10,656,000)
Net amount recognized		(11,146,000)	(11,885,000)
Amounts recognized in accumulated other comprehensive income before taxes:
Net actuarial loss		3,263,000	4,539,000
Prior service cost (benefit)		(8,418,000)	(11,793,000)
Net amount recognized		(5,155,000)	(7,254,000)
Total amount recognized in OCI
Net actuarial (gain)/loss		(292,000)	(2,939,000)
Prior service cost/(credit)			(12,218,000)
Amortization of:
Prior service cost/(credit)		3,375,000	7,268,000
Actuarial (gain)/loss		(983,000)	(882,000)
Total recognized in OCI		2,100,000	(8,771,000)
Components of the net periodic benefit cost
Service cost		50,000	476,000	452,000
Interest cost		457,000	1,114,000	1,481,000
Amortization of prior service cost		(3,375,000)	(1,754,000)	(1,205,000)
Recognized actuarial loss		983,000	882,000	553,000
Curtailment (benefits) expense			(5,514,000)	(338,000)
Net periodic benefit cost		(1,885,000)	(4,796,000)	943,000
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)				6.10%
Assumed health care cost trend rates
Annual rate of increase in the per capita cost of covered health care benefits (as a percent)	8.00%	8.50%
Annual rate of increase in the per capita cost of covered prescription drug benefits (as a percent)	7.00%	8.50%
For covered health care benefits, the ultimate rate to which the rate is assumed to decrease for 2019 and thereafter (2013 assumption) and for 2018 and thereafter (2012 assumption), as a percent	5.00%	5.00%
For covered prescription drug benefits, the ultimate rate to which the rate is assumed to decrease for 2017 and thereafter (2013 assumption) and for 2019 and thereafter (2012 assumption), as a percent	5.00%	5.00%
Effects of 1% change in assumed health care cost trend rate
Effect of 1% increase on benefit obligation		313,000
Effect of 1% increase on aggregate of the service and interest cost components of net periodic benefit cost		18,000
Effect of 1% decrease on benefit obligation		305,000
Effect of 1% decrease on aggregate of the service and interest cost components of net periodic benefit cost		18,000
Estimated future benefit payments
Expected contributions in next fiscal year		1,100,000
2013		1,141,000
2014		1,224,000
2015		1,212,000
2016		1,068,000
2017		946,000
2018-2022		$ 3,486,000
Other Benefits | Maximum
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)		5.05%	4.65%
Other Benefits | Minimum
Assumptions used to determine net periodic benefit cost
Discount rate (as a percent)		3.40%	3.50%