You may want to show detail views in separate windows instead of tabs. To accomplish this, let's review how tabs are created.
CollectionViewModelBase uses the IDocumentManagerService interface to create abstract documents that represent detail views at runtime. The implementation of IDocumentManagerService defines the way these views are represented in the UI. By default, the Tabbed MDI View Scaffolding Wizard generates the DepartmentContextView that uses the TabbedDocumentUIService to represent child Views in separate tabs within the DocumentGroup control.
All generated collection views already contain the WindowedDocumentUIService that shows views in separate windows. The YieldToParent property is set to true, which means that the CollectionViewModel will search its parent view models for the instance of the IDocumentManagerService interface.