EMPLOYEE BENEFITS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at beginning of year	$ 185,981
Balance at end of year	180,007	$ 185,981
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Pension and postretirement liabilities	(57,322)	(53,119)
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	235,433	216,306
Service cost	1,953	1,421	$ 1,401
Interest cost	6,676	8,426	7,380
Plan participants' contributions	1,516	1,501
Actuarial loss (gain)	(610)	34,840
Foreign currency impact	(2,197)	(11,792)
Benefits and administrative expenses paid	(8,619)	(11,985)
Settlements	(37)	(3,284)
Acquisitions	235	0
Benefit obligation at end of year	234,350	235,433	216,306
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at beginning of year	185,981	193,429
Actual return on plan assets	(597)	14,688
Employer contributions	3,362	2,644
Foreign currency impact	(1,599)	(11,012)
Balance at end of year	180,007	185,981	193,429
Funded status of plans	(54,343)	(49,452)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Non-current assets	1,638	2,318
Current liabilities	(264)	(253)
Pension and postretirement liabilities	(55,717)	(51,517)
Net amount recognized	(54,343)	(49,452)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]
Net actuarial (loss) gain	(80,641)	(75,220)
Transition asset	249	500
Prior service credit	1,804	2,126
Accumulated other comprehensive (loss) income	(78,588)	(72,594)
Accumulated contributions in excess of net periodic benefit cost	24,245	23,142
Net amount recognized	(54,343)	(49,452)
Defined Benefit Plan, Settlements, Plan Assets	37	3,284
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	1,806	1,769
Service cost	12	11	18
Interest cost	74	87	92
Plan participants' contributions	338	326
Actuarial loss (gain)	(100)	10
Foreign currency impact	0	0
Benefits and administrative expenses paid	(447)	(397)
Settlements	0	0
Acquisitions	0	0
Benefit obligation at end of year	1,683	1,806	1,769
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	109	71
Foreign currency impact	0	0
Balance at end of year	0	0	$ 0
Funded status of plans	(1,683)	(1,806)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Non-current assets	0	0
Current liabilities	(112)	(112)
Pension and postretirement liabilities	(1,571)	(1,694)
Net amount recognized	(1,683)	(1,806)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]
Net actuarial (loss) gain	706	657
Transition asset	0	0
Prior service credit	0	0
Accumulated other comprehensive (loss) income	706	657
Accumulated contributions in excess of net periodic benefit cost	(2,389)	(2,463)
Net amount recognized	(1,683)	(1,806)
Defined Benefit Plan, Settlements, Plan Assets	$ 0	$ 0