Question : How to show detail on summary report that is pulled into another report (sub-report)

How can I have one report that is a summary report pull into a main report and show it's detail?  The remaining reports that this report is pulled into need to only show  the summary data.  Do I HAVE to create a second Detail report?  I am not launching from a form, but can if need be, so there is no VB behind my action.

Answer : How to show detail on summary report that is pulled into another report (sub-report)

To clarify my comment and correct info;
"txtBox on MainReport control Source  = subReportControl.Report!summaryFieldOnSub"
what is there:
Reports:
MainReport (has text box txtSummary)
stDocName (has a field summary)
Drag stDocName onto MainReport, a subreport control is created called stDocName; it has fsummary and other fields.
txtSummary = stDocName.[Report].[summary]