Detention is determined on a customer-to customer basis. The expedite companies do NOT always charge the compaies for detention...it all depends on how their contracts are set up. Sometimes it's set up that the detention starts after the first hour, or 2 hours, I've even had a situation where we had to give up the first 3 hours, and of course, some don't get socked detention at all. It's best to immediately contact dispatch after the first hour to find out if you're getting detention and also ask how many hours do you have to 'donate' before detention starts.
I can tell you this: if you accept a load then sometime during that load, you decide that you, for whatever reason, decide that you no longer want it, the company WILL hold it against you and could possibly pull your contract. Once you accept the load, you are under obligation to complete the load. Obviously, being a SOLO driver and running out of legal hours is a different ball game BUT I'm basically referring to TEAMS. As a SOLO, the company will transfer the freight IF you run out of legal hours to finish the delivery. If you, as a TEAM, decide that you had enough of sitting at the shipper waiting to get loaded, so you want to get off the load, this is a different ball game and the carrier could pull your contract, shut you down for a certain amount of time, and do more. This will also go onto your record with that carrier and would hurt your reputation and possibly your career.
I've been in a situation where we sat at the shipper for over 6 hours and wasn't getting any detention. Even though I was mad as a wet hen, there was nothing I could do about it except to suck it up and shut up. Why? Because I made a commitment once I accepted that load and I was under full obligation to see it thru from beginning to end...no matter what happened and no matter how I felt. I, being me, kept a notebook that I called my "NO WAY IN HECK" book in which I kpet a list of customers that I would never haul freight for again...and not getting detention put this customer in that category.