Believe it or not, the drop down list is functioning as it was designed to--this just isn't what you want it to do.
Option 1: change the format from drop down list to pop up menu. The field will then display the name when you exit the field.
Option 2: Define a relationship based on this field that links your layout's table to the table from which your value list draws its values if you haven't already defined one. Add the name field from the related table to your portal row to display the name when you select the ID. If you want, you can use field behavior settings to prohibit access to this name field when in browse mode and place the field on top of the drop down list formatted field. When you click on this name field, the drop down list will pop to the front and deploy. When you select a company, the list will disappear back behind the name field and the name field will now display the name matching your selected ID.
Got it. I choose the first option which works perfectly with no problems.
Thanks for letting me know.