Summary of Employee Stock Options Activity (Parenthetical) (Detail) (Employee Stock Option, USD $)	Jun. 30, 2012
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award
Closing price of Quest Software, Inc.	$ 27.81

The final price at which a security is traded on a given trading day as reported on the NASDAQ National Market. The closing price represents the most up-to-date valuation of a security until trading commences again on the next trading day.

No definition available.

Name:	qsft_ClosingPrice
Namespace Prefix:	qsft_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant