How to add a column to standard content views

Hello. I'm new to SiteFinity. In the backend administration, how do I add a column to the default view for Document & Files? For example, we have a custom setting for "DocumentType" for our documents that I'd like to see in the list view, without having to open the document. The default columns are Title/Sttus, Translations, Actions, File/Dim/Size, Library/Categories/Tags, Owner, and Date. How can I add another one?

Shelly