Note 15 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Feb. 29, 2016		Feb. 28, 2015		Feb. 29, 2016	Feb. 28, 2015	Aug. 31, 2015
Tax Adjustments, Settlements, and Unusual Provisions	$ (7,300)		$ (5,100)
Effective Income Tax Rate Reconciliation, Percent	20.20%	[1]	24.10%	[2]	25.90%	27.40%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					35.00%
Unrecognized Tax Benefits	$ 8,488				$ 8,488		$ 6,776
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	1,600				1,600
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 900				$ 900

[1] On December 18, 2015, the U.S. Congress passed the Consolidated Appropriations Act, 2016 (the "2016 ACT"), which President Obama signed into law on the same day. The ACT reinstated and made permanent the U.S. Federal R&D tax credit (the "R&D tax credit"), which had previously expired on December 31, 2014. The reenactment of the R&D tax credit was retroactive to January 1, 2015 and by providing for a permanent R&D tax credit, the 2016 ACT eliminates the yearly uncertainty surrounding the extension of the credit. Prior to the reenactment of the R&D tax credit, FactSet had not been permitted to factor it into its effective tax rate as it was not currently enacted tax law. The reenactment resulted in a discrete income tax benefit of $7.3 million during the second quarter of fiscal 2016 and reduced the Company's effective tax rate for the quarter to 20.2%.

[2] On December 16, 2014, the U.S. Congress passed the Tax Increase Prevention Act of 2014 (the "2014 ACT"), which President Obama signed into law on December 19, 2014. The 2014 ACT reinstated the U.S. Federal R&D tax credit, which had previously expired on December 31, 2013. The reenactment of the credit was retroactive to January 1, 2014 and extended through the end of the 2014 calendar year. Prior to the reenactment of the tax credit, FactSet had not been permitted to factor it into its effective tax rate because it was not currently enacted tax law. The reenactment resulted in a discrete income tax benefit of $5.1 million during the second quarter of fiscal 2015 and reduced the Company's effective tax rate for the quarter to 24.1%.