Gets or sets a value indicating whether the LayoutDocuments can be repositioned in the LayoutDocumentPane via a drag of the LayoutDocumentTabItems, or if the LayoutAnchorables can be repositioned in the LayoutAnchorablePane via a drag of the LayoutAnchorableTabItems. (Inherited from Xceed.Wpf.AvalonDock.Layout.LayoutPositionableGroup<ILayoutPanelElement>)