CHANGES IN ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in AOCI by component
Beginning balance, net of tax	$ (38,801)	$ (1,419)	$ (25,509)
Other comprehensive (loss) income before reclassifications	(13,417)	(39,576)	23,183
Less income reclassified from AOCI	(2,874)	(1,239)	(2,522)
Net other comprehensive (loss) income	(10,543)	(38,337)	25,705
Income taxes	631	955	(1,615)
Ending balance, net of tax	(48,713)	(38,801)	(1,419)
Foreign currency translation adjustments
Changes in AOCI by component
Beginning balance, net of tax	25,913	38,663	36,830
Other comprehensive (loss) income before reclassifications	(4,598)	(11,893)	1,939
Less income reclassified from AOCI	0	0	0
Net other comprehensive (loss) income	(4,598)	(11,893)	1,939
Income taxes	786	857	106
Ending balance, net of tax	20,529	25,913	38,663
Retirement plans related adjustments
Changes in AOCI by component
Beginning balance, net of tax	(64,570)	(40,213)	(62,375)
Other comprehensive (loss) income before reclassifications	(8,607)	(27,551)	21,161
Less income reclassified from AOCI	(2,662)	(1,388)	(2,528)
Net other comprehensive (loss) income	(5,945)	(26,163)	23,689
Income taxes	(1,415)	(1,806)	1,527
Ending balance, net of tax	(69,100)	(64,570)	(40,213)
Unrealized gain (loss) on cash flow hedges
Changes in AOCI by component
Beginning balance, net of tax	(144)	131	36
Other comprehensive (loss) income before reclassifications	(212)	(132)	83
Less income reclassified from AOCI	(212)	149	6
Net other comprehensive (loss) income	0	(281)	77
Income taxes	(2)	(6)	(18)
Ending balance, net of tax	$ (142)	$ (144)	$ 131