Who is Jimmy Hoffa?

When Brock Lovett talking on phone he says:
-Hey, Dave, Barry, hi.Look, it wasn't in the an toàn, két an toàn ut hey, xin chào 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 an toàn, két an toàn on C deck.
And Bobby Buell says:
-Jimmy Hoffa's briefcase.

Who is Jimmy Hoffa?