Attorneys always suggest an idea might be patentable. :-) Unless you've got the specs for cold fusion or the hover board, worrying about protecting your idea is probably a waste of time. Patents are extremely difficult and expensive to protect. The only value I can imagine is through a later acquisition by a company that strategically needs just the patent you have. You're better off trying your luck in Vegas.
That's your idea. Then, there is execution...
Here in the Bay Area, and I've heard this is in contrast to other places, we have a culture of extreme openness. Entrepreneurs go around blabbing about their latest ideas all the time. Nobody really signs NDAs anymore. But everyone is comfortable talking about what they are doing. Know why that is? Because we all know that what counts is execution. The best entrepreneurs build talented teams because they are able to sell the vision to those teams, and lead them to execute on that vision. Here, talk is cheap, and patents are a distraction and a waste of time (again, there are exceptions, I'll admit. But I don't run into them very often).
The other thing is passion. When I advise people, they typically end up telling me their whole idea in the first coffee. I have a decade and a half of engineering experience and I am very well connected to other designers and engineers. I could put a team together and execute their vision. But I don't, and they aren't worried that I will. Why? Because I don't care about it as much as they do. It's their vision! At the end of the day, they are going to have to slog day and night through building the company. It's not just "a good idea", it's how you feel about the idea, and whether you're willing to do what it takes to make it real.
The final piece is feedback. The sooner you have shared your idea with other people who know how to build products and companies, the sooner you'll learn about all kinds of dangers, pitfalls and risks in your idea. If you keep it closer to your chest, you have less of a chance of learning about how valid the idea is, earlier on.
Go ahead and disclose what you're doing early and often (again, there are technical exceptions, but I doubt you're sitting on one). What you get from sharing information early is nearly always more valuable that what you're keeping secret.