Midwest - Overnight at DTW

Firstly, how easy is it to get a cab from Dearborn Amtrak station to DTW airport at 12am?

I then have the following flight at 6am. Is it possible to wait in the terminal between those times?

Thanks.

You will probably have to call for a cab at the train station. Taxis are not that common in the Detroit area, and if any are there when you arrive they have probably been pre-ordered by other passengers.

At the airport security is open 24/7, so you can get into the gate area if you are already checked in for your flight. If you need to check in, the ticket counter opens at either 4 or 5am. You could wait in the public area until then and probably not be disturbed.

I'd recommend waiting in the Lobby of the Westin for a bit if you can, it's got a nice ambiance...