Can you patent an “IDEA”?

p>I have a great idea. The challenge is that it will take millions to do complete R&D, Marketing, Sales, etc. The idea is an absolute winner and technologically feasible. I have an engineering background.

I would ideally like to just sell the "idea" to a bigger company that has the resources needed but I don’t want them to run with it and leave me in the cold. I spoke with a patent attorney and it would cost me a lot of $. My idea would require multiple technical patents. It also takes years. If I filed a provisional patent my understanding is that I would only have a year to come up with a working prototype or lose rights to the idea forever- is this true? I think it is beyond my means to make a working prototype (in order to file a non-provisional patent). I could make a non-functioning model to demonstrate the idea- how it would work in theory. It’s theoretically very simple and easy to understand (visualize). It would use existing and proven technologies but in a highly innovative new way. If my idea uses existing patents/process how would I address that (get permission to utilize them)? I see it getting expensive fast. This idea is worth the trouble. It’s practical, simple and it would be a major convenience and safety offering to end users; businesses and it would offer the investor a tremendous ROI.

THANK YOU!
SPOKE WITH A PATENT ATTORNEY= Talked to the lawyer and she said a single, SIMPLE patent (adding a clip on a pen) could cost k and take 3-5 years for an answer. My idea is FAR more complex and would involve multiple systems talking to one another (circuts, switches,etc.)- the result = AMAZING.
FYI- I have seen 5 of my other "ideas" go public already- I don’t want to miss out on this one- it’s my greatest idea to date.