Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013		Aug. 31, 2012		Aug. 31, 2011
Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues [Line Items]
Total Revenues	$ 219,332	$ 214,613	$ 213,083	$ 211,085	$ 207,663	$ 202,311	$ 199,371	$ 196,448	$ 858,112	[1]	$ 805,793	[1]	$ 726,510	[1]
United States [Member]
Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues [Line Items]
Total Revenues									586,865	[1]	550,474	[1]	497,564	[1]
United Kingdom [Member]
Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues [Line Items]
Total Revenues									121,072	[1]	114,435	[1]	104,698	[1]
All other European Countries [Member]
Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues [Line Items]
Total Revenues									87,755	[1]	82,969	[1]	73,995	[1]
Asia Pacific [Member]
Note 6 - Segment Information (Details) - Revenues From Countries That Are 10% Or More Of Revenues [Line Items]
Total Revenues									$ 62,420	[1]	$ 57,915	[1]	$ 50,253	[1]

[1] Revenues are attributed to countries based on the location of the client.