I did this a few months back. The best deal that I could find was to get an airport employee badge, and park in the employee lot. This will cost you $50, and is good for two years. Call the airport parking office to find out what kind of paperwork your airline needs to provide to verify that you are an airline employee.
I was able to bypass this by showing my employee travel card at the ticket counter, the ticket agent then filled out the form for me, and I took it down to the parking office (one, maybe two buildings west of the Terminal 1, ask around) to get my badge.
Once you have the badge, you can park in the employee lot and then take the bus over to the terminals. Depending on which terminal you're going to (Terminal 3 is the furthest by about 2 or 3 minutes.) it should take anywhere from 10-15 minutes to get to security. The buses run continuously and I have never waited for more than 5 minutes. Hope this helps.