If I have a great video game idea, what steps would I have to take in
order to get the idea to matriculate into a video game on the market,
while protecting my rights to the game?

Game companies don't buy ideas for games to to many reasons. You may
have a chance if ou actually get into the video game buinsness
yourself. Then you can sale the idea of the game to the company you
work for. Or you can learn to program and build it yourself.

Depending on the game you could always run it on flash. You wont get
the best anything but you can easily make games with flashmx.

First make sure that you elaborate your idea to the fullest possible
extent before you do anything else; this includes story, gameplay,
art, and anything else that you can think of to make it a complete
idea.

Second go to your local legislature office (city hall or some
government service building would know where to send you usually or
you can try to google a government website on copyright protection or
you could call up a lawyer! either of which should work!) and get a
itellectual property protection right (I believe that is how you spell
it) for your game idea! Do this before you meet with a
developer/producer. Why?

Third: Because to get someone to turn your idea into reality you have
to meet with someone who can do this and that is a developement studio
(or a production studio who owns a developement studio). I say get the
rights because if you meet with them and show them your idea and it is
not protected then those people can steal your idea and not have to
pay you a cent!

Fourth: Unfortunately the developement studio may just change your
idea enough just a tad bit and get away with stealing your idea
(although they don't always get away with it).  To face the facts!

Game companies really don't ever buy game ideas. Sorry :(

The closest thing I know that you could do to make your idea come to
life is by either
A: Learning how to program and doing it yourself or with a group of people!
or 
B: try going to moddb.com and make your game a mod! (also a good place
to get a group of people!)

Hope this helps

My husband's company : www.zemnott.com has built a lot of games.
Usually, a game distributer will already have an idea about a hole in
the market that they want to fill. For example, one company said
something like, "We want a game called "My Fantasy Wedding" that will
appeal to 6 to 9 year old girls." (It was something like this..I don't
recall the details." Then, we brainstormed a whole bunch of ideas, put
it into a proposal which they accepted and, like magic, it exists. You
can buy "My Fantasy Wedding" just about anywhere. Check out some other
games at www.slingdot.com if you want to see examples of Flash and
Shockwave games. You really need to know what you're doing - and have
a lot of people working on this stuff to make it work. Or, if you're
independently wealthy you could try to build it yourself, but most
large retailers won't take a product from an independent designer.
You'd have to maybe market it on the internet.