Within your Report do as follows;
a) Add a Group to the Report - Group by your ID
b) Add a Formula field that Sums the Amounts by your ID - the formula should look like below
Sum({TableName.Amount},{TableName.ID})
c) Add your Formula field to the Group Header - position the field to the right of your Amount field
d) Open Section Expert and select the Group Header
e) Select the option "Underlay following sections"
Kind Regards