CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Changes in AOCI by component
Beginning balance, net of tax	$ (46,485)	$ (33,797)	$ (48,713)	$ (38,801)
Other comprehensive (loss) income before reclassifications	1,307	(6,975)	2,036	(2,295)
Less income reclassified from AOCI	(1,434)	(803)	(3,038)	(1,957)
Net other comprehensive (loss) income	2,741	(6,172)	5,074	(338)
Income taxes	(322)	506	(427)	(324)
Ending balance, net of tax	(44,066)	(39,463)	(44,066)	(39,463)
Foreign currency translation adjustments
Changes in AOCI by component
Beginning balance, net of tax	21,359	30,487	20,529	25,913
Other comprehensive (loss) income before reclassifications	(368)	(7,169)	531	(1,641)
Less income reclassified from AOCI	0	0	0	0
Net other comprehensive (loss) income	(368)	(7,169)	531	(1,641)
Income taxes	256	(625)	325	329
Ending balance, net of tax	20,735	23,943	20,735	23,943
Retirement plans related adjustments
Changes in AOCI by component
Beginning balance, net of tax	(67,815)	(64,418)	(69,100)	(64,570)
Other comprehensive (loss) income before reclassifications	1,471	1,087	1,185	(258)
Less income reclassified from AOCI	(1,560)	(661)	(3,148)	(1,994)
Net other comprehensive (loss) income	3,031	1,748	4,333	1,736
Income taxes	53	218	70	54
Ending balance, net of tax	(64,837)	(62,888)	(64,837)	(62,888)
Unrealized gain (loss) on cash flow hedges
Changes in AOCI by component
Beginning balance, net of tax	(29)	134	(142)	(144)
Other comprehensive (loss) income before reclassifications	204	(893)	320	(396)
Less income reclassified from AOCI	126	(142)	110	37
Net other comprehensive (loss) income	78	(751)	210	(433)
Income taxes	13	(99)	32	(59)
Ending balance, net of tax	$ 36	$ (518)	$ 36	$ (518)