Enable the ability to add custom fields to Idea Portal Users Merged

We are a B2B business and we would like to report on the ideas submitted by each of the business customers who submitted the idea. We would like to have the ability to setup a custom field for "Business Name" when setting up access to our Idea Portal. This will enable our sales and executive teams to see the enhancements submitted by each one of our clients and be able to show what we have accomplished for them.