Exporting vectors to pdf

I have a map that includes the "North American Detailed Streets" layer.

I'm using Arcmap 10.2. When I export to pdf, my streets become rasters.
Previously, in either 10.0 or 10.1, when I used the same map it exported vectors. I have tried changing every setting on the export dialog and no matter what I do I can't seem to get vectors.

Any advice?

EDIT: Windows 7