To resize the detached view
To resize the docked view
Drag the edge of the view you want to move with the mouse. Right-click (Mac OS: Ctrl+click) the title bar of the view and choose the edge you want to move from the popup menu, e.g. choose Size > Left to move the left edge of the view.
The corresponding edge of the view will be emphasized with blue. Now you can resize the view by dragging the selected edge.