How can you share a great business idea with potential partners/investors without them walking & stealing it?

Let's say you have a breakthrough business idea. And there's immense value in it simply because the idea hasn't found its way in the real world yet. And likely no-one's thought of it just yet, because this idea could have been materialized or commercialized even years ago!!!!! And the idea is simple and would take only a few seconds to describe, though it might take a lot (or perhaps not so much even) of work and money to implement. But the idea is so great that it could easily translate into millions or billions of dollars of new revenues, creating almost an entirely new market in an existing industry. Now let's say you want to capitalize on the value of the idea (which would take just a few seconds to disclose or describe or make known) by shopping for investors/partners/buyers, but which of course would require disclosure of the idea. How would you go about sharing the idea with others and at the same time prevent them from simply taking it and running off with it ?????