I disagree with the last bit. If the idea is a good one, and you want it to be implemented, then fine, keep it hush hush. But, if it's a good one, and you want it to succeed, then it'd be best to get stakeholder involvment, irregardless of the politics involved. I've seen way too many 'ideas' which seemed good in theory, but failed in implementation because stakeholders weren't consulted. One of the most critical success factors in making something suceed is buy in. And I don't mean just from the stakeholders, but the owners as well. You need buy in, irregardless of how good the idea is.