You're right in being concerned about protecting your idea. If you share this with others you should have them at least sign a contract (like NDA - non-disclosure agreement) to protect your idea. But keep in mind that if they did share your idea you'd need to spend the $$$ to sue 'em.
May want to keep the idea 'close to the vest' and try to get your idea developed in parts (so others couldn't determine the overall idea).
Hope that helped!
█ Josh Ramos
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