Jessica has a point on the idea. There is a significant chasm between an idea and money in the bank. there will be lots of money spent in not just the patent but the implementation and maturation of the idea. Anyone that sees your idea will need to spend that money and if they took it from you open themselves up to other legal issues. In the filing and documenting of the patent process you will realize other claims that will apply and you will want those included. I own a patent on the automatic sealing of aircraft wings. However, in perfecting this for industry I realized that there were other fine details and advantages that I need to include for it to work on the factory floor. Now I need to protect them as well. So you will learn more about your idea as you perfect it for commercial applications. The point is you will learn more about your invention as you work out the details and you really want all of these ideas included in the final patent protecting all of the IP, not just the initial idea. If you want to protect your idea without spending a lot of money up front and you really want some credibility with investors then file a provisional patent on line with the USPTO. that will give you a year to file the final patent. whatever you do take a lot of notes, time stamp everything in those notes and be able to show how you arrived at the idea. here are some other ideas in this link. good luck and you can never get too much exposure.