RETIREMENT AND DEFERRED COMPENSATION PLANS (Details) € in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 EUR (€)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 EUR (€)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Level 3 | Hedge Fund
Change in plan assets:
Fair value of plan assets at beginning of year		$ 272		$ 9,731
Fair value of plan assets at end of year		0		272	$ 9,731
Plan Assets:
Total Investments		272		9,731	9,731	$ 0		$ 272	$ 9,731
Level 3 | Infrastructure
Change in plan assets:
Fair value of plan assets at beginning of year		8,931		8,587
Fair value of plan assets at end of year		8,960		8,931	8,587
Plan Assets:
Total Investments		8,931		8,587	8,587	8,960		8,931	$ 8,587
Domestic Plans
Change in benefit obligation:
Benefit obligation at beginning of year		171,501		129,448
Service cost		10,016		8,042	8,539
Interest cost		6,355		5,928	4,992
Actuarial (gain) loss		(19,568)		33,058
Benefits paid		(7,309)		(4,975)
Benefit obligation at end of year		160,995		171,501	129,448
Change in plan assets:
Fair value of plan assets at beginning of year		111,094		100,567
Actual return on plan assets		(930)		5,431
Employer contribution		10,079		10,071
Benefits paid		(7,309)		(4,975)
Fair value of plan assets at end of year		112,934		111,094	100,567
Funded status at end of year						(48,060)		(60,407)
Funded status amounts recognized in Consolidated Balance Sheet
Current liabilities						(173)		(471)
Non-current liabilities						(47,887)		(59,936)
Funded status amount						(48,060)		(60,407)
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss						47,820		64,272
Tax effects						(17,933)		(24,102)
Net amount recognized						29,887		40,170
Changes in benefit obligations and plan assets recognized in other comprehensive income
Current year actuarial gain		11,048		(34,211)	20,548
Amortization of net loss		5,404		2,869	5,103
Amortization of prior service cost					3
Net amount recognized		16,452		(31,342)	25,654
Amounts in accumulated other comprehensive loss expected to be recognized as components of periodic benefit cost in 2016
Amortization of net loss		2,988
Amount expected to be recognized in next fiscal year		2,988
Components of net periodic benefit cost:
Service cost		10,016		8,042	8,539
Interest cost		6,355		5,928	4,992
Expected return on plan assets		(7,590)		(6,585)	(5,775)
Amortization of net loss		5,404		2,869	5,103
Amortization of prior service cost					3
Net periodic benefit cost		$ 14,185		$ 10,254	$ 12,862
Accumulated benefit obligation						145,500		153,800
Projected benefit obligation ("PBO"), ABO, and fair value of plan assets for all pension plans with an ABO in excess of plan assets
Projected benefit obligation						160,995		171,501
Accumulated benefit obligation						145,482		153,778
Fair value of plan assets						112,934		111,094
PBO, ABO, and fair value of plan assets for all pension plans with a PBO in excess of plan assets
Projected benefit obligation						160,995		171,501
Accumulated benefit obligation						145,482		153,778
Fair value of plan assets						$ 112,934		$ 111,094
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)						4.24%	3.83%	3.83%	4.75%
Rate of compensation increase (as a percent)						4.00%	4.00%	4.00%	4.00%
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate (as a percent)	3.83%	3.83%	4.75%	4.75%	3.80%
Expected long-term return on plan assets (as a percent)	7.00%	7.00%	7.00%	7.00%	7.00%
Rate of compensation increase (as a percent)	4.00%	4.00%	4.00%	4.00%	4.00%
Plan Assets:
Weighted-average asset allocations (as a percent)						100.00%	100.00%	100.00%
Total Investments		$ 111,094		$ 100,567	$ 100,567	$ 112,934		$ 111,094	$ 100,567
Minimum funding requirement		0
Expected contribution in next fiscal year		10,000
Domestic Plans | Cash and Short Term Securities
Change in plan assets:
Fair value of plan assets at beginning of year		3,190
Fair value of plan assets at end of year		1,189		3,190
Plan Assets:
Total Investments		3,190		3,190		$ 1,189		$ 3,190
Domestic Plans | Equity Securities
Change in plan assets:
Fair value of plan assets at beginning of year		52,840
Fair value of plan assets at end of year		$ 53,985		52,840
Plan Assets:
Weighted-average asset allocations (as a percent)						47.00%	47.00%	47.00%
Target allocation (as a percent)	60.00%	60.00%
Total Investments		$ 52,840		52,840		$ 53,985		$ 52,840
Domestic Plans | Fixed Income
Change in plan assets:
Fair value of plan assets at beginning of year		29,762
Fair value of plan assets at end of year		33,291		29,762
Plan Assets:
Weighted-average asset allocations (as a percent)						30.00%	27.00%	27.00%
Total Investments		29,762		29,762		$ 33,291		$ 29,762
Domestic Plans | Hedge Fund
Change in plan assets:
Fair value of plan assets at beginning of year		16,371
Fair value of plan assets at end of year		15,509		16,371
Plan Assets:
Weighted-average asset allocations (as a percent)						14.00%	15.00%	15.00%
Total Investments		16,371		16,371		$ 15,509		$ 16,371
Domestic Plans | Infrastructure
Change in plan assets:
Fair value of plan assets at beginning of year		8,931
Fair value of plan assets at end of year		8,960		8,931
Plan Assets:
Weighted-average asset allocations (as a percent)						8.00%	8.00%	8.00%
Total Investments		$ 8,931		8,931		$ 8,960		$ 8,931
Domestic Plans | Money market
Plan Assets:
Weighted-average asset allocations (as a percent)						1.00%	3.00%	3.00%
Domestic Plans | Fixed income securities and infrastructure
Plan Assets:
Target allocation (as a percent)	40.00%	40.00%
Domestic Plans | Level 1
Change in plan assets:
Fair value of plan assets at beginning of year		$ 75,743
Fair value of plan assets at end of year		70,832		75,743
Plan Assets:
Total Investments		75,743		75,743		$ 70,832		$ 75,743
Domestic Plans | Level 1 | Cash and Short Term Securities
Change in plan assets:
Fair value of plan assets at beginning of year		3,190
Fair value of plan assets at end of year		1,189		3,190
Plan Assets:
Total Investments		3,190		3,190		1,189		3,190
Domestic Plans | Level 1 | Cash and Short Term Securities | USD
Change in plan assets:
Fair value of plan assets at beginning of year		3,190
Fair value of plan assets at end of year		1,189		3,190
Plan Assets:
Total Investments		3,190		3,190		1,189		3,190
Domestic Plans | Level 1 | Equity Securities
Change in plan assets:
Fair value of plan assets at beginning of year		52,840
Fair value of plan assets at end of year		47,725		52,840
Plan Assets:
Total Investments		52,840		52,840		47,725		52,840
Domestic Plans | Level 1 | US Large Cap Equities
Change in plan assets:
Fair value of plan assets at beginning of year		29,381
Fair value of plan assets at end of year		28,797		29,381
Plan Assets:
Total Investments		29,381		29,381		28,797		29,381
Domestic Plans | Level 1 | US Small Cap Equities
Change in plan assets:
Fair value of plan assets at beginning of year		8,493
Fair value of plan assets at end of year		5,349		8,493
Plan Assets:
Total Investments		8,493		8,493		5,349		8,493
Domestic Plans | Level 1 | International Equities
Change in plan assets:
Fair value of plan assets at beginning of year		14,966
Fair value of plan assets at end of year		13,579		14,966
Plan Assets:
Total Investments		14,966		14,966		13,579		14,966
Domestic Plans | Level 1 | Fixed Income
Change in plan assets:
Fair value of plan assets at beginning of year		19,713
Fair value of plan assets at end of year		21,918		19,713
Plan Assets:
Total Investments		19,713		19,713		21,918		19,713
Domestic Plans | Level 2
Change in plan assets:
Fair value of plan assets at beginning of year		26,148
Fair value of plan assets at end of year		33,142		26,148
Plan Assets:
Total Investments		26,148		26,148		33,142		26,148
Domestic Plans | Level 2 | Equity Securities
Change in plan assets:
Fair value of plan assets at end of year		6,260
Plan Assets:
Total Investments		6,260				6,260
Domestic Plans | Level 2 | Equity Securites Global Equities
Change in plan assets:
Fair value of plan assets at end of year		6,260
Plan Assets:
Total Investments		6,260				6,260
Domestic Plans | Level 2 | Fixed Income
Change in plan assets:
Fair value of plan assets at beginning of year		10,049
Fair value of plan assets at end of year		11,373		10,049
Plan Assets:
Total Investments		10,049		10,049		11,373		10,049
Domestic Plans | Level 2 | Hedge Fund
Change in plan assets:
Fair value of plan assets at beginning of year		16,099
Fair value of plan assets at end of year		15,509		16,099
Plan Assets:
Total Investments		16,099		16,099		15,509		16,099
Domestic Plans | Level 3
Change in plan assets:
Fair value of plan assets at beginning of year		9,203
Fair value of plan assets at end of year		8,960		9,203
Plan Assets:
Total Investments		9,203		9,203		8,960		9,203
Domestic Plans | Level 3 | Hedge Fund
Change in plan assets:
Fair value of plan assets at beginning of year		272
Fair value of plan assets at end of year				272
Plan Assets:
Total Investments		272		272				272
Domestic Plans | Level 3 | Infrastructure
Change in plan assets:
Fair value of plan assets at beginning of year		8,931
Fair value of plan assets at end of year		8,960		8,931
Plan Assets:
Total Investments		8,931		8,931		8,960		8,931
Foreign Plans
Change in benefit obligation:
Benefit obligation at beginning of year		91,160		84,660
Service cost		4,570		4,186	3,901
Interest cost		1,654		2,711	2,676
Curtailment/Settlement		(227)
Prior service cost		821
Actuarial (gain) loss		(1,486)		14,765
Benefits paid		(2,265)		(3,111)
Foreign currency translation adjustment		(9,420)		(12,051)
Benefit obligation at end of year		84,807		91,160	84,660
Change in plan assets:
Fair value of plan assets at beginning of year		55,394		54,075
Actual return on plan assets		927		2,875
Employer contribution		10,157		8,016
Benefits paid		(2,265)		(3,111)
Foreign currency translation adjustment		(5,696)		(6,461)
Fair value of plan assets at end of year		58,517		55,394	54,075
Funded status at end of year						(26,288)		(35,766)
Funded status amounts recognized in Consolidated Balance Sheet
Non-current liabilities						(26,288)		(35,766)
Funded status amount						(26,288)		(35,766)
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss						33,839		36,219
Net prior service cost						4,036		3,471
Tax effects						(12,211)		(12,762)
Net amount recognized						25,664		26,928
Changes in benefit obligations and plan assets recognized in other comprehensive income
Current year actuarial gain		568		(12,589)	3,005
Current year prior service cost		(821)
Amortization of net loss		1,812		1,214	1,416
Amortization of prior service cost		256		313	373
Net amount recognized		1,815		(11,062)	4,794
Amounts in accumulated other comprehensive loss expected to be recognized as components of periodic benefit cost in 2016
Amortization of net loss		1,510
Amortization of prior service cost		343
Amount expected to be recognized in next fiscal year		1,853
Components of net periodic benefit cost:
Service cost		4,570		4,186	3,901
Interest cost		1,654		2,711	2,676
Expected return on plan assets		(1,792)		(1,979)	(1,821)
Amortization of net loss		1,676		1,214	1,416
Amortization of prior service cost		256		313	373
Net periodic benefit cost		6,364		6,445	6,545
Settlement		136
Curtailment					1
Total net periodic benefit cost		$ 6,500		$ 6,445	$ 6,546
Accumulated benefit obligation						65,500		70,700
Projected benefit obligation ("PBO"), ABO, and fair value of plan assets for all pension plans with an ABO in excess of plan assets
Projected benefit obligation						81,343		87,759
Accumulated benefit obligation						61,990		67,317
Fair value of plan assets						55,054		51,993
PBO, ABO, and fair value of plan assets for all pension plans with a PBO in excess of plan assets
Projected benefit obligation						81,343		87,759
Accumulated benefit obligation						61,990		67,317
Fair value of plan assets						$ 55,054		$ 51,993
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)						2.10%	1.90%	1.90%	3.24%
Rate of compensation increase (as a percent)						3.00%	3.00%	3.00%	3.00%
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate (as a percent)	1.90%	1.90%	3.24%	3.24%	3.19%
Expected long-term return on plan assets (as a percent)	3.54%	3.54%	3.79%	3.79%	3.79%
Rate of compensation increase (as a percent)	3.00%	3.00%	3.00%	3.00%	3.00%
Plan Assets:
Weighted-average asset allocations (as a percent)						100.00%	100.00%	100.00%
Total Investments		$ 55,394		$ 54,075	$ 54,075	$ 58,517		$ 55,394	$ 54,075
Expected contribution in next fiscal year		5,000
Foreign Plans | Cash and Short Term Securities
Change in plan assets:
Fair value of plan assets at beginning of year		1,289
Fair value of plan assets at end of year		1,907		1,289
Plan Assets:
Total Investments		1,289		1,289		$ 1,907		$ 1,289
Foreign Plans | Equity Securities
Change in plan assets:
Fair value of plan assets at beginning of year		2,625
Fair value of plan assets at end of year		2,258		2,625
Plan Assets:
Weighted-average asset allocations (as a percent)						4.00%	5.00%	5.00%
Total Investments		2,625		2,625		$ 2,258		$ 2,625
Foreign Plans | Fixed Income
Change in plan assets:
Fair value of plan assets at beginning of year		574
Fair value of plan assets at end of year		559		574
Plan Assets:
Weighted-average asset allocations (as a percent)						1.00%	1.00%	1.00%
Total Investments		574		574		$ 559		$ 574
Foreign Plans | Corporate debts securities
Change in plan assets:
Fair value of plan assets at beginning of year		6,758
Fair value of plan assets at end of year		1,542		6,758
Plan Assets:
Weighted-average asset allocations (as a percent)						3.00%	12.00%	12.00%
Total Investments		6,758		6,758		$ 1,542		$ 6,758
Foreign Plans | Investment Funds
Change in plan assets:
Fair value of plan assets at beginning of year		44,148
Fair value of plan assets at end of year		$ 52,251		44,148
Plan Assets:
Weighted-average asset allocations (as a percent)						89.00%	80.00%	80.00%
Target allocation (as a percent)	100.00%	100.00%
Total Investments		$ 44,148		44,148		$ 52,251		$ 44,148
Foreign Plans | Money market
Plan Assets:
Weighted-average asset allocations (as a percent)						3.00%	2.00%	2.00%
Foreign Plans | Level 1
Change in plan assets:
Fair value of plan assets at beginning of year		25,889
Fair value of plan assets at end of year		25,712		25,889
Plan Assets:
Total Investments		25,889		25,889		$ 25,712		$ 25,889
Foreign Plans | Level 1 | Cash and Short Term Securities
Change in plan assets:
Fair value of plan assets at beginning of year		1,289
Fair value of plan assets at end of year		1,907		1,289
Plan Assets:
Total Investments		1,289		1,289		1,907		1,289
Foreign Plans | Level 1 | Cash and Short Term Securities | EUR
Change in plan assets:
Fair value of plan assets at beginning of year | €	€ 1,289
Fair value of plan assets at end of year		1,907	€ 1,289
Plan Assets:
Total Investments	€ 1,289	1,907	€ 1,289			1,907	€ 1,289
Foreign Plans | Level 1 | Equity Securities
Change in plan assets:
Fair value of plan assets at beginning of year		2,625
Fair value of plan assets at end of year		2,258		2,625
Plan Assets:
Total Investments		2,625		2,625		2,258		2,625
Foreign Plans | Level 1 | US Small Cap Equities
Change in plan assets:
Fair value of plan assets at end of year		2,258
Plan Assets:
Total Investments		2,258				2,258
Foreign Plans | Level 1 | International Equities
Change in plan assets:
Fair value of plan assets at beginning of year		2,625
Fair value of plan assets at end of year				2,625
Plan Assets:
Total Investments		2,625		2,625				2,625
Foreign Plans | Level 1 | Fixed Income
Change in plan assets:
Fair value of plan assets at beginning of year		574
Fair value of plan assets at end of year		559		574
Plan Assets:
Total Investments		574		574		559		574
Foreign Plans | Level 1 | Corporate debts securities
Change in plan assets:
Fair value of plan assets at beginning of year		6,758
Fair value of plan assets at end of year		1,542		6,758
Plan Assets:
Total Investments		6,758		6,758		1,542		6,758
Foreign Plans | Level 1 | Euro Corporate Bonds
Change in plan assets:
Fair value of plan assets at beginning of year		6,758
Fair value of plan assets at end of year		1,542		6,758
Plan Assets:
Total Investments		6,758		6,758		1,542		6,758
Foreign Plans | Level 1 | Investment Funds
Change in plan assets:
Fair value of plan assets at beginning of year		14,643
Fair value of plan assets at end of year		19,446		14,643
Plan Assets:
Total Investments		14,643		14,643		19,446		14,643
Foreign Plans | Level 1 | Mutual Funds in Equities
Change in plan assets:
Fair value of plan assets at beginning of year		2,687
Fair value of plan assets at end of year		3,392		2,687
Plan Assets:
Total Investments		2,687		2,687		3,392		2,687
Foreign Plans | Level 1 | Mutual Funds in Bonds
Change in plan assets:
Fair value of plan assets at beginning of year		11,386
Fair value of plan assets at end of year		15,501		11,386
Plan Assets:
Total Investments		11,386		11,386		15,501		11,386
Foreign Plans | Level 1 | Mutual Funds Diversified
Change in plan assets:
Fair value of plan assets at beginning of year		570
Fair value of plan assets at end of year		553		570
Plan Assets:
Total Investments		570		570		553		570
Foreign Plans | Level 2
Change in plan assets:
Fair value of plan assets at beginning of year		29,505
Fair value of plan assets at end of year		32,805		29,505
Plan Assets:
Total Investments		29,505		29,505		32,805		29,505
Foreign Plans | Level 2 | Investment Funds
Change in plan assets:
Fair value of plan assets at beginning of year		29,505
Fair value of plan assets at end of year		32,805		29,505
Plan Assets:
Total Investments		29,505		29,505		32,805		29,505
Foreign Plans | Level 2 | Mutual Funds Diversified
Change in plan assets:
Fair value of plan assets at beginning of year		29,505
Fair value of plan assets at end of year		32,805		29,505
Plan Assets:
Total Investments		$ 29,505		$ 29,505		32,805		29,505
Non-qualified supplemental pension plan
Non-qualified supplemental pension plan information
Non funded liability						$ 8,400		$ 8,500