Who is Jimmy Hoffa?

When Brock Lovett talking on phone he says:
-Hey, Dave, Barry, hi.Look, it wasn't in the безопасно, сейф ut hey, Эй, on't worry about it. There's still plenty of places it could be. Hell yes! Floor debris in the suite, the mother's room, purser's безопасно, сейф on C deck.
And Bobby Buell says:
-Jimmy Hoffa's briefcase.

Who is Jimmy Hoffa?