Do I need a copyright on the idea that I want to sign a nondisclosure for?

One cannot copyright an idea.  Instead one can copyright the manifestation of that idea.  So for instance, no one can copyright, trademark or patent the idea of a soft drink; one can however protect the idea of "Coca Cola".  So in this case, you need to manifest the idea in a different way.  Can you improve on the idea?  Can you "tweak" it enough to change how the idea is viewed by the public?    In reference to the non-disclosure, you can always ask that the recipient of the idea refrain from using it.  But as noted above, if all you have is the idea, but no way to "deliver" the idea to the public, then the non-disclosure will be of little use.  On the other hand, if you have indeed created a product from the idea, then the non-disclosure will be a worthwhile pursuit. Michael J. Katz Corporon & Katz Aurora, Colorado