When looking at the Journal Items for the opening period on Opening Entries Journal, I see the total amount of accounts:

440000 suppliers

400000 customers

How can I find out which customer or supplier is having an outstanding amount?

We are already working in fiscal year 2016 now and the opening journal is related to fiscal year 2015.

So looking at the account invoices at that time is not an option.

Odoo version 7.0