Note 14. Employee Stock Option and Retirement Plans (Detail) - Summary of Stock Option Activity (USD $)	0 Months Ended	1 Months Ended			0 Months Ended	1 Months Ended		3 Months Ended								12 Months Ended					14 Months Ended
	Jan. 14, 2011	Jul. 31, 2012	Nov. 30, 2011	Nov. 30, 2010	Jan. 15, 2010	Oct. 31, 2009	Aug. 31, 2008	Aug. 31, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Aug. 31, 2010	Feb. 28, 2010	Nov. 30, 2009	Aug. 31, 2012		Aug. 31, 2011	Aug. 31, 2010		Jul. 31, 2011
Number outstanding									6,132,000						7,553,000	6,132,000		6,451,000	7,553,000
Weighted average exercise price per share (in Dollars per share)									$ 57.28						$ 39.51	$ 57.28		$ 47.73	$ 39.51
Granted, Number outstanding	14,514	241,546	665,551	734,334	18,510	900,665	1,058,981			17,842	6,408	65,224	820,202	297,483		1,468,513		998,038	2,069,336		204,508
Granted, Weighted average exercise price per share (in Dollars per share)								$ 90.92	$ 94.84	$ 96.10	$ 103.30	$ 99.78	$ 67.41	$ 63.09	$ 66.46
Exercised, Number outstanding																(731,000)		(1,209,000)	(1,980,000)
Exercised, Weighted average exercise price per share (in Dollars per share)																$ 35.96		$ 32.08	$ 25.77
Forfeited, Number outstanding																(786,000)	[1]	(108,000)	(1,191,000)	[2]
Forfeited, Weighted average exercise price per share (in Dollars per share)																$ 87.37	[1]	$ 66.55	$ 64.47	[2]
Number outstanding								6,083,000		6,132,000			6,451,000			6,083,000		6,132,000	6,451,000
Weighted average exercise price per share (in Dollars per share)								$ 64.76		$ 57.28			$ 47.73			$ 64.76		$ 57.28	$ 47.73
Performance Based [Member]
Granted, Number outstanding																907,000
Granted, Weighted average exercise price per share (in Dollars per share)																$ 93.80
Non-Performance Based [Member]
Granted, Number outstanding																540,000		91,000	329,000
Granted, Weighted average exercise price per share (in Dollars per share)																$ 93.96		$ 89.45	$ 63.42
Performance Based [Member]
Granted, Number outstanding																		892,000	1,721,000
Granted, Weighted average exercise price per share (in Dollars per share)																		$ 89.39	$ 66.91
Non-Employee Directors [Member]
Granted, Number outstanding																21,000		15,000	19,000
Granted, Weighted average exercise price per share (in Dollars per share)																$ 87.26		$ 95.05	$ 66.81

[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.