Note 7 - Segment Information (Details Textual) $ in Thousands	12 Months Ended
Aug. 31, 2018 USD ($)	Aug. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
Number of Reportable Segments	3
Goodwill, Ending Balance	$ 701,833	$ 707,560	$ 452,915
UNITED STATES
Goodwill, Ending Balance	$ 386,195	386,835	367,480
Goodwill Percentage Per Segment	54.00%
Europe [Member]
Goodwill, Ending Balance	$ 312,694	317,759	82,280
Goodwill Percentage Per Segment	45.00%
Asia Pacific [Member]
Goodwill, Ending Balance	$ 2,944	$ 2,966	$ 3,155
Goodwill Percentage Per Segment	1.00%

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant