Accounting Policies, by Policy (Policies)	3 Months Ended
Nov. 30, 2013
Accounting Policies [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Standards or Updates Recently Adopted Balance Sheet Offsetting In December 2011, the FASB issued an accounting standard update requiring enhanced disclosures about certain financial instruments and derivative instruments that are offset in the balance sheet or that are subject to enforceable master netting arrangements or similar agreements. In January 2013, the FASB issued a clarifying accounting standard update, which limited the scope of the previous guidance to only derivatives, repurchase type agreements and securities borrowing and lending transactions. These accounting standard updates were effective for FactSet beginning in the first quarter of fiscal 2014, and the additional disclosure has been included in Note 5, Derivative Instruments. Indefinite-lived Intangible Assets In July 2012, the FASB issued an accounting standard update intended to simplify how an entity tests indefinite-lived intangible assets other than goodwill for impairment by providing entities with an option to perform a qualitative assessment to determine whether further impairment testing is necessary. This accounting standard update became effective for FactSet beginning in the first quarter of fiscal 2014 and did not have an impact on the Company’s consolidated financial statements. Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income In February 2013, the FASB issued an accounting standard update to require reclassification adjustments from other comprehensive income to be presented either in the financial statements or in the notes to the financial statements. This accounting standard update became effective for FactSet beginning in the first quarter of fiscal 2014 and the additional information has been disclosed in Note 6, Accumulated Other Comprehensive Loss. Cumulative Translation Adjustments In March 2013, the FASB issued an accounting standard update requiring an entity to release into net income the entire amount of a cumulative translation adjustment related to its investment in a foreign entity when as a parent it either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. This accounting standard update was adopted by FactSet beginning in the first quarter of fiscal 2014 and did not have an impact on the Company’s consolidated financial statements. No other new accounting pronouncements issued or effective as of November 30, 2013 have had or are expected to have an impact on the Company’s consolidated financial statements. In addition, there were no recent accounting standards or updates not yet effective for the Company as of November 30, 2013.

Accounting Policies, by Policy (Policies)

3 Months Ended

Nov. 30, 2013

Description of New Accounting Pronouncements Not yet Adopted [Text Block]

New Accounting Standards or Updates Recently Adopted

Balance Sheet Offsetting

In December 2011, the FASB issued an accounting standard update requiring enhanced disclosures about certain financial instruments and derivative instruments that are offset in the balance sheet or that are subject to enforceable master netting arrangements or similar agreements. In January 2013, the FASB issued a clarifying accounting standard update, which limited the scope of the previous guidance to only derivatives, repurchase type agreements and securities borrowing and lending transactions. These accounting standard updates were effective for FactSet beginning in the first quarter of fiscal 2014, and the additional disclosure has been included in Note 5, Derivative Instruments.

Indefinite-lived Intangible Assets

In July 2012, the FASB issued an accounting standard update intended to simplify how an entity tests indefinite-lived intangible assets other than goodwill for impairment by providing entities with an option to perform a qualitative assessment to determine whether further impairment testing is necessary. This accounting standard update became effective for FactSet beginning in the first quarter of fiscal 2014 and did not have an impact on the Company’s consolidated financial statements.

Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income

In February 2013, the FASB issued an accounting standard update to require reclassification adjustments from other comprehensive income to be presented either in the financial statements or in the notes to the financial statements. This accounting standard update became effective for FactSet beginning in the first quarter of fiscal 2014 and the additional information has been disclosed in Note 6, Accumulated Other Comprehensive Loss.

Cumulative Translation Adjustments

In March 2013, the FASB issued an accounting standard update requiring an entity to release into net income the entire amount of a cumulative translation adjustment related to its investment in a foreign entity when as a parent it either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets within a foreign entity. This accounting standard update was adopted by FactSet beginning in the first quarter of fiscal 2014 and did not have an impact on the Company’s consolidated financial statements.

No other new accounting pronouncements issued or effective as of November 30, 2013 have had or are expected to have an impact on the Company’s consolidated financial statements. In addition, there were no recent accounting standards or updates not yet effective for the Company as of November 30, 2013.