Under the Account Details on the "Licensor Details" page, you have 2 fields, Balance & Turnover.
The Balance field displays the amount of royalties that have been invoiced for yet isn't paid. So this is the total amount of royalties for that licensor that is awaiting payment once they have submitted an invoice.
The turnover is the royalties that are allocated to invoices for that licensor that are marked as paid.
Note: Neither the Balance or Turnover is the amount that is unpaid to that licensor unless they have submitted an invoice. To see the amount outstanding for that licensor click the "Submit Invoice Page" link at the top of the "Licensor Details" page. This will show a sum of the total outstanding royalties waiting to be invoiced for that licensor.