Note 14. Employee Stock Option and Retirement Plans (Detail) - Summary of Share-Based Awards Available For Grant	1 Months Ended	12 Months Ended
	Nov. 30, 2010	Aug. 31, 2012		Aug. 31, 2011		Aug. 31, 2010
Amendment to the 2004 Stock Option and Award Plan to increase the number of shares available for issuance***	4,000,000
Granted				154,281
Share-based awards canceled/forfeited		(786,000)	[1]	(108,000)		(1,191,000)	[2]
Balance	1,000,000
Employee Option Plan [Member] | Non-Performance Based [Member]
Granted		(540,000)		(91,000)		(329,000)
Employee Option Plan [Member] | Performance-Based Stock Options [Member]
Granted		(907,000)		(892,000)		(1,721,000)
Employee Option Plan [Member]
Balance		4,977,000		2,216,000		4,124,000
Share-based awards expired**						(395,000)	[3]
Amendment to the 2004 Stock Option and Award Plan to increase the number of shares available for issuance***				4,000,000	[4]
Restricted stock awards granted			[5]	(386,000)	[5]	(667,000)	[5]
Share-based awards canceled/forfeited		810,000		130,000		1,204,000
Balance		4,340,000		4,977,000		2,216,000
Non-Employee Stock Option Plan [Member] | Non-Employee Directors [Member]
Granted		(21,000)		(15,000)		(19,000)
Non-Employee Stock Option Plan [Member]
Balance		147,000		162,000		181,000
Share-based awards expired**							[3]
Amendment to the 2004 Stock Option and Award Plan to increase the number of shares available for issuance***					[4]
Restricted stock awards granted			[5]		[5]		[5]
Balance		126,000		147,000		162,000

[1] In August 2007, the Company granted 896,194 performance-based employee stock options. None of these performance-based stock options granted vested because FactSet did not achieve certain performance levels for both organic ASV and diluted earnings per share during the two fiscal years ended August 31, 2009. As such, these performance-based stock options were recorded as forfeitures in August 2009.

[2] In August 2008, the Company granted 1,058,981 performance-based employee stock options. None of these performance-based stock options granted vested because FactSet did not achieve certain performance levels for both organic ASV and diluted earnings per share during the two fiscal years ended August 31, 2010. As such, these performance-based stock options were recorded as forfeitures in August 2010.

[3] Represents the remaining stock options available for grant within the Company's 2000 Stock Option plan that expired in January 2010 because they were never granted.

[4] As of November 30, 2010, 1.0 million shares remained available for future grant of share-based awards under the Company's 2004 Stock Option and Award Plan, a number that the Company believed to be insufficient to meet its anticipated needs over the next 12 to 18 months. Therefore, the Company's Board of Directors approved, subject to stockholder approval, an amendment to increase the maximum number of shares of FactSet common stock issuable under the 2004 Stock Option and Award Plan by 4,000,000 shares. The stockholders of FactSet voted on and approved the Amended and Restated FactSet Research Systems Inc. 2004 Stock Option and Award Plan at the Company's annual meeting held on December 14, 2010, including the reservation of an additional 4,000,000 shares of common stock for issuance.

[5] For each share awarded as restricted stock under the Company's Option Plans, an equivalent of 2.5 shares were deducted from the available share-based awards balance.