Note 15. Income Taxes (Detail) (USD $)	1 Months Ended	3 Months Ended
	Jan. 31, 2013	Nov. 30, 2012		Nov. 30, 2011	Aug. 31, 2012
Income Tax Reconciliation, Repatriation of Foreign Earnings (in Dollars)	$ 1,300,000
Effective Income Tax Rate, Continuing Operations		30.40%	[1]	32.10%
Effective Income Tax Reconciliation Basis Points				130
Unrecognized Tax Benefits (in Dollars)		5,699,000			5,464,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued (in Dollars)		$ 1,100,000
Before Discrete Items [Member]
Effective Income Tax Rate, Continuing Operations		32.20%
Effective Income Tax Reconciliation Basis Points		10
Expiration of the US Federal R&D Tax Credit [Member]
Effective Income Tax Reconciliation Basis Points		180

[1] In the first quarter of fiscal 2013 FactSet decided to repatriate cash from its wholly owned UK subsidiary. This distribution was completed in early January 2013 and resulted in a net tax benefit of approximately $1.3 million during the three months ended November 30, 2012 since the foreign tax credits associated with the distribution were greater than the tax due on the distribution of the foreign earnings. The first quarter fiscal 2013 effective tax rate before the discrete item of $1.3 million was 32.2% or 10 basis points higher than the 2012 effective tax rate. The expiration of the U.S. Federal R&D tax credit on December 31, 2011 negatively impacted the fiscal 2013 first quarter effective tax rate by 180 basis points compared to 130 basis points in the year ago first quarter.