Steve Coogan has signed on to join the cast of My Idiot Brother , reports Deadline .The film, currently shooting in New York, stars Paul Rudd who, trying to escape his overbearing mother, spends some time staying with each of his three sisters (Elizabeth Banks, Zooey Deschanel and Emily Mortimer). Coogan (who appears next in The Other Guys ) will play "a self-righteous documentary filmmaker".Directed by Jesse Peretz (2007's The Ex ), ...