Note 15. Income Taxes (Detail) (USD $)	1 Months Ended	3 Months Ended			6 Months Ended
	Jan. 31, 2013	Feb. 28, 2013		Feb. 29, 2012	Feb. 28, 2013		Feb. 29, 2012	Aug. 31, 2012
Unrecognized Tax Benefits, Decreases Resulting from Current Period Tax Positions		$ 4,900,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate		29.90%
Effective Income Tax Rate, Continuing Operations		21.20%	[1]	30.90%	26.30%	[2]	31.50%
Unrecognized Tax Benefits, Increases Resulting from Acquisition	1,300,000
Unrecognized Tax Benefits		5,346,000			5,346,000			5,464,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		$ 1,200,000			$ 1,200,000

[1] On January 1, 2013, the U.S. Congress passed the American Taxpayer Relief Act of 2012 (the "ACT"), which President Obama signed into law on January 2, 2013. While the ACT did not change corporate tax rates, it did reenact the U.S. Federal R&D tax credit, which had previously expired on December 31, 2011. The reenactment of the credit was retroactive to January 1, 2012 and extends through the end of the 2013 calendar year. As a result, discrete income tax benefits of $4.9 million were recognized by the Company during the second quarter of fiscal 2013 because prior to the reenactment of the tax credit, FactSet had not been permitted to factor it into its effective tax rate as it was not currently enacted tax law. The $4.9 million of income tax benefits reduced the Company's effective tax rate from 29.9% to 21.2% during the second quarter of fiscal 2013.

[2] In the first quarter of fiscal 2013 FactSet decided to repatriate cash from its wholly owned UK subsidiary. This distribution was completed in fiscal 2013 and resulted in a net tax benefit of approximately $1.3 million during the first six months of fiscal 2013 since the foreign tax credits associated with the distribution were greater than the tax due on the distribution of the foreign earnings.