NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedule of Reclassifications

Comparative information for the years ended December 31, 2016 and 2015 follows:

	Year Ended December 31, 2016
	As Reported				After Reclassification
	(in thousands except percentages)
United States	$	605,856	52.2	%	$	611,392	52.7	%
United Kingdom	174,719		15.1	%	177,194		15.3	%
Switzerland	122,399		10.6	%	122,919		10.6	%
Canada	58,742		5.1	%	59,189		5.1	%
Germany	43,216		3.7	%	43,621		3.8	%
Russia	40,866		3.5	%	40,944		3.5	%
Sweden	22,945		2.0	%	23,838		2.1	%
Hong Kong	20,333		1.8	%	21,010		1.8	%
Netherlands	16,762		1.4	%	17,521		1.5	%
Belgium	8,505		0.7	%	8,627		0.7	%
Ireland	5,152		0.4	%	5,167		0.4	%
China	4,445		0.4	%	4,479		0.4	%
Italy	3,970		0.3	%	4,052		0.3	%
United Arab Emirates	3,486		0.3	%	3,615		0.3	%
Other locations	16,215		1.4	%	16,564		1.5	%
Reimbursable expenses and other revenues	12,521		1.1	%	—		—	%
Total	$	1,160,132	100.0	%	$	1,160,132	100.0	%

	Year Ended December 31, 2015
	As Reported				After Reclassification
	(in thousands except percentages)
United States	$	427,433	46.8	%	$	431,992	47.3	%
United Kingdom	164,301		18.0	%	166,418		18.2	%
Switzerland	111,353		12.2	%	111,686		12.2	%
Canada	57,643		6.3	%	58,319		6.4	%
Germany	36,089		3.9	%	36,403		4.0	%
Russia	36,506		4.0	%	36,585		4.0	%
Sweden	10,589		1.2	%	10,775		1.2	%
Hong Kong	23,117		2.5	%	23,285		2.5	%
Netherlands	9,989		1.1	%	10,373		1.1	%
Belgium	7,916		0.9	%	8,113		0.9	%
Ireland	5,437		0.6	%	5,536		0.6	%
Italy	2,318		0.3	%	2,342		0.3	%
China	817		0.1	%	817		0.1	%
Other locations	11,109		1.1	%	11,484		1.2	%
Reimbursable expenses and other revenues	9,511		1.0	%	—		—	%
Total	$	914,128	100.0	%	$	914,128	100.0	%