In 2012, patent law in the United States changed. The U.S. is now a "first to file" nation. That simply means that the patent for an innovation or product goes to the first person to file patent paperwork, not the first inventor. On a practical level, that means you need to file for a patent as soon as possible. Keep in mind that you can still file a provisional patent before filing for a full one. That way, you'll still be considered the first to file, even if you haven't worked out every detail.