CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Changes in AOCI by component
Beginning balance, net of tax	$ (38,226)	$ (54,656)
Other comprehensive (loss) income before reclassifications	3,986	3,771
Total before tax	(555)	(994)
Net other comprehensive (loss) income	4,541	4,765
Income tax expense	35	419
Ending balance, net of tax	(33,720)	(50,310)
Foreign currency translation adjustments
Changes in AOCI by component
Beginning balance, net of tax	25,349	15,483
Other comprehensive (loss) income before reclassifications	4,058	4,258
Total before tax	0	0
Net other comprehensive (loss) income	4,058	4,258
Income tax expense	15	417
Ending balance, net of tax	29,392	19,324
Retirement plans related adjustments
Changes in AOCI by component
Beginning balance, net of tax	(63,203)	(70,102)
Other comprehensive (loss) income before reclassifications	(663)	(569)
Total before tax	(724)	(845)
Net other comprehensive (loss) income	61	276
Income tax expense	(47)	(10)
Ending balance, net of tax	(63,095)	(69,816)
Unrealized gain (loss) on cash flow hedges
Changes in AOCI by component
Beginning balance, net of tax	(372)	(37)
Other comprehensive (loss) income before reclassifications	591	82
Total before tax	169	(149)
Net other comprehensive (loss) income	422	231
Income tax expense	67	12
Ending balance, net of tax	$ (17)	$ 182