It can be done with the Content Migration Manager. It's free and really not that tough to set up and can be done w/o teamcenter.
Drawings seem to come over fine. I have used I-deas extensively and only dabbled in NX. But i did transfer a decent size assembly and all the part and related drawings. If i changed a migrated part the drawing updated. I have never made a part in NX and an associated drawing from scratch. Figured i could figure that out later if we converted to NX.
