You can configure the Document Search Results list to always open documents in a new window, instead of opening in the Document Viewer below the list.
To always open documents in a new window, click the Open in New Window toggle button in the results list pane.
The Document Viewer is removed, and the button icon changes to indicate the setting is enabled. When you open a document from the list, it will be opened in a new window.
Click the Open in New Window button again to toggle back to opening documents in the Document Viewer. The button icon changes back to indicate the setting is disabled.