How to ask the Statistics Report to export detail lines

I select the Statistics Report and specify the Expense view and Category (BY) to aggregate. This opens up a window with the list of categories with their subtotals which is a summary report. I highlight one of the categories and select the Toggle Detail button which brings up all the detail records for the category selected in a pane underneath the pane that contains the category totals. I then select the Export as CSV button hoping to export the detail records in the lower pane but all that gets exported are the contents of the upper pane which contains only the summary records. What I really want is the detail records to be exported to CSV and I cannot figure how accomplish this.

Thanks in advance for your help.