A ToolWindow is considered floating when it is not contained within the bounds of the DockHost. At any time, a docked tool window can become floating by double-clicking in the tool window's caption or by dragging it until its drop-cue indicates that its state will be floating. Interactively, tool windows can become floating at any time unless the Dock-layout Manager's AllowFloating property is set to false. 

The size of a tool window is limited by the rectangle defined by the FloatingWindowBounds property. For example, if a tool window has a size of 500x200 pixels and its FloatingWindowBounds property is set to 300x150 pixels, then if/when the tool window becomes floating, it will have a size of 300x150 pixels. If another tool window is docked with the floating tool window, the size of the new tool window will also be limited by the FloatingWindowBounds defined by the target tool window and will not surpass 50% of the target tool window's size. Once the tool window is docked with the target floating tool window, it can be resized interactively or via its Size property. If a ToolWindow is docked with a floating ToolWindow, then its state is considered to be floating and not docked.