I think nowaday is not the idea one should "protect". These days everybody has many ideas. The real value today is to succesfully develop the idea into a product or service which delivers value.

So just start working on it, show it to other people, try to find somebody who works on it with you (a developer), and collect some feedback.

Don't be affraid! If it is really a good idea, it's surely gonna be copied by others. :)