I am working on a webapp that is largely datagrids. When a row of the data grid is selected a detail pane slides up from the bottom of the app that displays various information related to the selected row. My issue is most of the information is also datagrids, usually with many rows and quite wide (wider than the browser requiring horizontal scrollbars). But occasionally I need to display more vertical information, such as a form. I had thought about having the form split into two columns when there is space but I have never found two column forms to be very usable. Do I have to suck it up and have a vertical form in a very horizontal space (with vertical scrolling) or is there an ingenious idea someone has that I haven't thought of?
Edit (additional info): Not shown in the mockup is a selector in the detail pane that allows the user to switch between a number of "pages" of information. Some of the detail pages are datagrids as they represent tabular information that is editable, while some of the detail pages are standard forms as they do not represent tabular information. All of the pages are expanded detail based on the selection in the main ddatagrid. To make things even more complicated the user can select more than one row from the main datagrid and make changes to the detail pages that will affect all items selected.