VBA-check if text is outside of paragraph text box?

I want to be able to check if the text in a paragraph text box is too large for the box and goes outside of it (when the border turns red).  Is there a way to do this with VBA?

I see there is a property called "IsInsideContainer", so I want to be able to do something like this, but I can't get it to work:

If cdrTextBox.Text <> IsInsideContainer Then


End If