What can I do to protect myself?

while it may be too late to get them to sign written agreements,normally you would get something called a nondisclosure agreement in place prior to disclosing an idea to the company. Without that, you will probably have to establish a written communication trail that provides that you disclosed this idea to them with the intention that you would be compensated if they exploited the idea for commercial purposes. In Florida there was a case several years ago involving Walt Disney World and the wide world of sports complex that was built there. The creators of the idea were given a judgment against Walt Disney World. You might want to try to look that up to get an idea of some of the issues and possibly the difficulties in documenting your claim sufficiently. If appropriate, you might also want to consider disclosing the idea to a competitor that might also be interested in adopting it and trying to get a nondisclosure agreement out of them. However, these types of communications become very difficult with large corporations because they get bogged down in layers of bureaucracy and discussions with corporate counsel, etc. You should use an attorney to help you wade through this and try to get as much protection as possible at this point in your discussions and negotiations. This is specific to Florida law and does not constitute legal advice as the facts presented are anonymous and incomplete. This is intended for general education only and does not create an attorney-client relationship. This should not be relied on and you must seek your own attorney client relationship.