While you can not turn off Delve completely, you can choose to hide all of documents from within Delve.
- When in the Delve app online, click on Settings (the gear icon in the upper-right corner)
- Go to "Feature Settings" and select Off for "Documents"
- You can also turn off "MyAnalytics" or "Email Digest" as desired.
- Click OK to save the changes.
Note: The changes to hide documents are not immediate. They can take up to a week for them to be removed from the Delve application.