Note 8 - Goodwill and Intangible Assets - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Balance		$ 669,719	$ 635,565
Acquisitions of businesses, net		46,202	38,765
Impairment	$ (4,611)		(4,611)
Balance	669,719	704,640	669,719
Foreign currency translation		(11,281)
Goodwill, gross				$ 1,212,444	$ 1,177,523
Accumulated impairment				(507,804)	(507,804)
Goodwill	669,719	669,719	635,565	704,640	669,719
Domestic [Member]
Balance		621,451	582,686
Acquisitions of businesses, net			38,765
Impairment
Balance	621,451	621,451	621,451
Foreign currency translation
Goodwill, gross				1,124,644	1,124,644
Accumulated impairment				(503,193)	(503,193)
Goodwill	621,451	621,451	582,686	621,451	621,451
International [Member]
Balance		48,268	52,879
Acquisitions of businesses, net		46,202
Impairment			(4,611)
Balance	48,268	83,189	48,268
Foreign currency translation		(11,281)
Goodwill, gross				87,800	52,879
Accumulated impairment				(4,611)	(4,611)
Goodwill	$ 48,268	$ 48,268	$ 52,879	$ 83,189	$ 48,268

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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