Pitch idea to current company or go elsewhere

In a bit of dilemma - looking to crowdsource some wisdom: I'm currently working at a medium sized company that itself is looking to pivot. I think i've come up with a pretty strong idea that could either fit for this company, a few others in this space, or even start my own company. What is the best play here? So far I got: 1) I pitch this to my current employer. They have the resources to build it, are already in a similar space, and are exploring ways to pivot the business. However best case seems to be they say, "Great, build it" and I get to do something else than my usual day to day. Though most likely I'd just get an additional job. Might get a promotion/bonus but not a substantial increase in equity/ownership. 2) I pitch this to another company in the space who might be interested. 3) I build this out myself. I have the technical skills to at least put together a decent MVP in 1-2 months. Some other analysis: 1) Legally, if my current employer wanted to fight me for ownership they'd have a decent case. My contract says they own what I invent and the idea is sufficiently close to the current lines of business that I don't think CA moonlighting law(2870) would help me too much. That said, the idea is a combination of concepts and I'm not sure all parts of it could be considered related. I imagine it'd depend on the caselaw and the scope of 'relates'. 2) I could build out a MVP on the side and then present it the current company as an independent project - asking, innocently, if they might be interested in acquiring it. Not crazy about this plan as it's actually one i've sort of done before with limited success. Still, seems like it might work. If they say no I could take it elsewhere and I could see them wanting it if only to prevent that and could offer at minimum whatever the costs/headaches of legal action might be. Thoughts? Asking on a throw away for obvious reasons.