It won the Jury Prize in the Cannes Film Festival last year, and the NY Times gave it a good review, but I don't think the movie was played nationwide here in the US. It opened in Manhattan, in April, and perhaps a few other major cities ran it, but certainly not in the smaller cities and towns. Limited release I would say.
It came out on DVD here August 13th. It's also available on Amazon...what isn't though...and I am waiting for my copy to arrive. Should be an interesting watch I think. I hear the dialogue is subtitled because of the thick Glaswegian brogues of some of the actors.