Erlang Plugin turns IntelliJ IDEA and other IntelliJ-based products (RubyMine, PyCharm, WebStorm, etc.) to a convenient Erlang IDE.
Download the latest successful plugin, hit 'Install plugin from disk...' at 'Plugins' page in 'Settings' of your IDE, and point it to the downloaded archive.
Note for Mac OS X users: you need to download the entire zip file, not a several jars (see Apple discussion forum).