STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Pension and Postretirement Medical Benefits	$ (65,644)	$ (75,781)	$ (32,547)	$ (122,246)
Available for Sale Securities	(1,325)	413	0	57
Foreign currency translation adjustment	(69,901)	(17,880)	0	0
Tax Effect of Other Comprehensive Income Gains	(34,430)	(31,048)	(31,048)	(26,156)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(171,300)	(124,296)	(63,595)	$ (148,345)
Pension And Postretirement Medical Benefits	10,137	(43,234)	89,699
Available For Sale Securities	(1,738)	413	(57)
Foreign Currency Translation Adjustment	(52,021)	(17,880)	0
Tax effect of other comprehensive income gains	(3,382)	0	(4,892)
Other comprehensive income (loss)	$ (47,004)	$ (60,701)	$ 84,750