I don't have any programming skills, nor do I have the time to learn them[/quote]
Nuh-uh. If people could make games (above gamemaker-style level) without knowing any programming, it would be known. If you really can't spare any time to learn, then your best bet is to hire a developer (need to get him interested first) or get a friend to do it with you. Otherwise you really need to learn some programming if you want to make it yourself, and it does take a while. That's just how it is, you can't have something for nothing (a.k.a. there is no such thing as a free lunch).

Secondly, have you looked online for similar games, there's a very significant probability someone has already made exactly the game you describe (and possibly already milked it, if it was successful). That doesn't necessarily mean you shouldn't proceed, though, but it might be something to consider.

If you are looking for actual partners instead of how to learn the basics of programming, then this should go into Classifieds (Help Wanted).

don't have any programming skills, nor do I have the time to learn them, but I'm stubborn

Well, as Bacterius stated, this will be ..uhhm... challenging. The "idea guy" and even the "game designer" will have a hart time to get his game idea realised. Take a look at this [s]sad [/s]interesting discussion about game ideas and game designers.

Over the past couple weeks I've been kicking around in my head an idea that I personally think can make a great game. I don't have any programming skills, nor do I have the time to learn them, but I'm stubborn and I want to make this thing a reality. Without going into too much detail it would be a shooter, 1st or 3rd hasn't been decided yet. It wouldn't really be open world, but would be open ended. Think along the lines of the original X-Com. It would be class based and it would center around co-op play. And finally, I know they're getting used a bit too much in pop culture right now, but it would be a zombie game. Let me know if anyone is able and interested in helping, and we can go over more of the details.

If you are stubborn then learning how to use an engine like Unity3D should be perfectly possible. (It doesn't take that long so not having time is no excuse (Learning how to use Unity takes far less time than making the actual game).

Let me know if anyone is able and interested in helping, and we can go over more of the details.

Recruiting is not permitted outside the Classifieds. Don't do that anymore. Use the Classifieds.

Is there a way to show this to people to get opinions without the risk of it being stolen?

look i know you feel pretty unique and all that. but if you spend just a little fraction of your day using the search function on this website you will discover that, actually, no, you are not unique at all.
You're following the very same pattern most people like you follow when they show up with a great idea.. the sooner you'll realize that your idea is worth nothing until somebody (hint.. and that would be YOU ;) ) turns that into a computer software, the better.

Just reading around should clarify you a couple of very important bullet points:

1) Nobody will work for you on your idea
2) If you want somebody to work for you on your idea, get the cash ready
3) No cash? Read point 1
4) If you really want to get your idea going.. learn some basics coding or tool. Get a prototype up, show that you can do stuff.
5) GDD. If you're doing it because you think it's fun then by all means go on and do it. But it won't bring you anything, nobody will read it, let alone steal it.
6) The art of computer gaming is in the execution <- THIS ONE! Doing stuff is the real deal, thinking about stuff is.. nothing really

Failing to understand these things will just make you the Nth new user with a "great idea" that will end up leaving frustrated... seriously, use the search button and save yourself the agony.