How do you pitch a news show idea to the large news networks?

-I have a brilliant idea for a political news commentary show Ala Crossfire, hardball, etc. Assume it's good (which i believe it is), does anybody know the process for pitching the idea to CNN, FoxNews, Cspan, etc? Do they accept show ideas from other parties or is it all done internally?



If anybody knows the answer could you also info on the process AFTER the pitch as well, ie would they work with me to get the show going? Would they just take the idea, or could i remain involved? etc etc.



Thanks,

Sam