Somethign like this should work:
<browser:page
for="plone.app.contenttypes.interfaces.IDocument"
name="document_view"
template="document.pt"
class=".views.DocumentView"
permission="zope2.View"
layer="plonetheme.mytheme.interfaces.IPlonethemeMythemeLayer"
/>
Where the template document.pt and the class inside .views are located where configure is. Probably you will also need to make your layer inherite from: IPloneAppContenttypesLayer so your layer has more priority, like this:
from plone.app.contenttypes.interfaces import IPloneAppContenttypesLayer
class IPlonethemeMythemeLayer(IDefaultBrowserLayer, IPloneAppContenttypesLayer):
"""Marker interface that defines a browser layer.
"""
Other option is to register a view with a different name and change the default view of the Document