It's not that easy, Production companies recieve on average 10,000 'unsolicited' ideas a year, if they are a company that accepts unsolicited ideas yours will join a pile of about 6,000 which are read in the order they arrived and binned in the same order.
I'm sure you're idea is a good one, most trash on TV is because broadcasters hold meetings with the producers of these independent production companies and say "The weekest link is a winner, come back & present me with something on these lines, but isn't the same". That's what the commissioning editors of the BBC, Chanel 4, ITV do. The producers go to their 'in house development teams' or people they've worked with previously and devise something to pitch for commissioning. Rarely is this put the the average joe. Be prepared for a long, long wait, and a response if you are lucky. Everyone who works in the media has 'ideas'.. There is no reason why you couldn't pitch your idea yourself to the commissioners, but you would have to produce it too, providing detailed budgeting plans & research etc.. And make it happen yourself. Good luck.