STOCKHOLDERS' EQUITY (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Changes in accumulated other comprehensive income (loss), net of tax
Beginning Balance	$ 5,137	$ (26,778)	$ (15,886)
Before-Tax Amount	(54,177)	54,929	(18,699)
Tax Benefit (Expense)	16,358	(23,014)	7,807
Total other comprehensive income (loss), net of tax	(37,819)	31,915	(10,892)
Ending Balance	(32,682)	5,137	(26,778)
Pension and other postretirement liability adjustment
Changes in accumulated other comprehensive income (loss), net of tax
Beginning Balance	(9,229)	(45,958)	(33,600)
Before-Tax Amount	(41,906)	59,743	(20,165)
Tax Benefit (Expense)	16,358	(23,014)	7,807
Total other comprehensive income (loss), net of tax	(25,548)	36,729	(12,358)
Ending Balance	(34,777)	(9,229)	(45,958)
Foreign currency translation adjustment
Changes in accumulated other comprehensive income (loss), net of tax
Beginning Balance	14,366	19,180	17,714
Before-Tax Amount	(12,271)	(4,814)	1,466
Tax Benefit (Expense)	0	0	0
Total other comprehensive income (loss), net of tax	(12,271)	(4,814)	1,466
Ending Balance	$ 2,095	$ 14,366	$ 19,180