In order to create XBRL taxonomy extensions for text content, the corresponding content must be selected in the "Preview" tab. After the corresponding text content is selected, an XBRL taxonomy extension can be created by clicking on the second button from the left hand side toolbar.
It is important to set the "Item Type" to "Textblock" as well as adjust the other properties of the newly created extension as shown in the image below. If other text content should be tagged with the same extension (creating a continuation, which needs to be done manually in this instance) it is important to use the exact same "Element Name".