Carson27:
Since you are using feet & inches, you will need to type the "-" a second time to move the dimension line to the left (you would type the "+" to move it to the right). The first "-" is the separator between feet & inches, the second "-" is to input the direction of the offset.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David