This article will help show you how to find stale documents.

Step-by-Step Guide

Within the SharePoint Essentials Toolkit, you can utilize the “Item Query” feature to find any type of text or content easily.

Open the SharePoint Essentials Toolkit
Select the sites that you want to find stale items for, then right click and select "Create Reports->Item Query"
The Item Query job options page will appear as below
Give the Job a name that describes what we are doing, such as "Find Stale Files and Folders"
Change the drop down to use "Last Modified" is "Is Less than or equal to" (or "greater than or equal to") and enter a value for N Months Ago or other time frame
(Optional) You can specify additional SharePoint Columns to pull metadata from, by clicking "Advanced Options", then enter "Additional Fields"
(Optional) You can click "Advanced Options" to exclude or only Include specific Lists.
Click "Run Now", the job will run and query every site and list selected.
Once done, there will be a button called "Open Report", click "Open Report" to view the results
The report will show you results for all items that have not been modified in 6 months.

NOTE: In below screenshot it is set to "Created less than 1 month ago"

Cognillo Technical Support