You can choose to cancel existing documents from the model.
The detail drawings have a correlation to the model drawings. Due to this correlation, the Document Manager always knows which drawings belong to the respective projects. In some cases, for example if a drawing is not requested for the moment, you can cancel existing drawings from the model. The correlation between the detail drawing and the model drawing will be lost. However, you can restore it by registering the drawings to the model.
Access the command
In the Output tab 
Document Manager panel, click
(Cancel documents from the model).
Command line: _AstorDetDeRegist
Cancel a drawing from the model
- In the Output tab Document Manager panel, click
(Cancel documents from the model). The file selection dialog box appears.
- Browse to the folder where the .dwg is stored.
- Select the file to cancel from the model.
- Click OK.
- The drawing is no longer available in the Document Manager.