CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in AOCI by component
Beginning balance, net of tax	$ (44,905)	$ (37,747)	$ (48,713)	$ (38,801)
Other comprehensive (loss) income before reclassifications	(2,161)	3,009	728	4,681
Less income reclassified from AOCI	(863)	(608)	(1,605)	(1,154)
Net other comprehensive (loss) income	(1,298)	3,617	2,333	5,835
Income taxes	(282)	333	(105)	(831)
Ending balance, net of tax	(46,485)	(33,797)	(46,485)	(33,797)
Foreign currency translation adjustments
Changes in AOCI by component
Beginning balance, net of tax	24,312	26,090	20,529	25,913
Other comprehensive (loss) income before reclassifications	(2,840)	4,196	899	5,528
Less income reclassified from AOCI	0	0	0	0
Net other comprehensive (loss) income	(2,840)	4,196	899	5,528
Income taxes	113	(201)	69	954
Ending balance, net of tax	21,359	30,487	21,359	30,487
Retirement plans related adjustments
Changes in AOCI by component
Beginning balance, net of tax	(69,221)	(64,014)	(69,100)	(64,570)
Other comprehensive (loss) income before reclassifications	775	(1,191)	(287)	(1,344)
Less income reclassified from AOCI	(800)	(669)	(1,589)	(1,333)
Net other comprehensive (loss) income	1,575	(522)	1,302	(11)
Income taxes	169	(118)	17	(163)
Ending balance, net of tax	(67,815)	(64,418)	(67,815)	(64,418)
Unrealized gain (loss) on cash flow hedges
Changes in AOCI by component
Beginning balance, net of tax	4	177	(142)	(144)
Other comprehensive (loss) income before reclassifications	(96)	4	116	497
Less income reclassified from AOCI	(63)	61	(16)	179
Net other comprehensive (loss) income	(33)	(57)	132	318
Income taxes	0	(14)	19	40
Ending balance, net of tax	$ (29)	$ 134	$ (29)	$ 134