Note 3 - Acquisitions (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Number of Businesses Acquired	10	9	9
Business Combination, Acquisition Related Costs	$ 2,794	$ 5,301	$ 9,103
Business Acquisition, Goodwill, Expected Tax Deductible Amount	18,837	25,745	712
Business Combination, Contingent Consideration, Liability	32,266
Acquisitions after December 31 2008 [Member]
Business Combination, Contingent Consideration, Liability	32,266
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	65,519
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	72,798
Contingent Consideration Paid	2,018	$ 6,083	$ 25,535
Acquisitions after December 31 2008 [Member] \| Contingent Consideration, Compensation Element [Member]
Business Combination, Contingent Consideration, Liability	$ 5,335
Americas [Member]
Number of Businesses Acquired	6
EMEA [Member]
Number of Businesses Acquired	4

The contingent consideration paid.

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- Definition

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

+ References

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e1043-128460

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- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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For contingent consideration arrangements and indemnification assets recognized in connection with a business combination, this element represents an estimate of the low-end of the potential range (undiscounted) of the consideration which may be paid.

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- Definition

Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 35
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

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- Definition

The number of businesses acquired by the entity during the period.

+ References

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