This is a pretty good entry in the "Dumb People Committing Crimes" genre. At least I laughed all the way through. It is based on an actual $17 million heist, although considerable liberties were taken to make things funnier. Co-produced by Lorne Michaels, it's also a movie gig for a lot of ex-SNL cast members.
Zach Galifianakis (could equally well have been Will Forte) plays probably the dumbest guy, David Ghantt, a trusted employee of an armored car company. When slightly-smarter Steve (Owen Wilson) learns that David is smitten with his co-worker Kelly (Kristen Wiig), a plot is hatched. And it goes surprisingly well! David goes on the lam down to Mexico. Steve, with the lion's share of the loot, realizes that David is a loose end, and sends a hitman (Jason Sudekis) after him.
Also: Kate McKinnon as David's spacey fiancée; Leslie Jones as an FBI agent. Everybody's funny, and the movie is better than it probably deserves to be.