What would you do here?

Local tournament at my casino. Early, I have about 6,000 in chips in my big blind. Player to my right has been playing like an idiot all night. He's drunk, playing every hand, and several times he's gone all-in pre-flop, only to have everyone fold as he shows down 7-4o. Blinds are at 100-200, and it's my BB, a few limpers and guess what? Moron goes all-in again. I have A [img]/images/graemlins/spade.gif[/img]K [img]/images/graemlins/heart.gif[/img]. And by the way, he got stupid lucky early so he has a big stack and has me covered. What would you do here? After I get a few posts, I'll tell you what I did and explain why.