It's your idea, so other people probably won't be as excited about it as you, else someone else would have had that idea before you. Hence, the probability that others will steal the idea is not that big.
It's rather the opposite: You will have to convince or pay someone else to actually help you implement it, if you are lacking the skills!
I know at least from my company (Bosch), that we share our private ideas in our internal company network and see if someone else is interested in helping create a company-internal startup in order to make a product out of it. So far, no ideas were stolen or leaked and most stuff just lies around, because aint nobody got time to convince others. And hell, there are some good ideas!