I was fully expecting IntelliJ CE to have this supported out of the box, however it didn't seem to be the case. Perhaps it's additional in the ultimate edition, I don't know (yet). I was able to follow the directions on http://stackoverflow.com/questions/4145734/jdk-documentation-in-intellij-idea-on-mac-os-x in order to get this to work.
For posterity, I've copied in the directions that worked here as well:
Chris Williams said:
I had to combine the responses I got to this point and add a few extra details so I'm answering my own question.
- I had to login to Apple's Developer Downloads
- Select "Downloads" under "Browse" and then "Java" under "Downloads".
- Download and install "Java for Mac OS X 10.6 Update 3 Developer Package".
- In IntelliJ, open File -> Project Structure.
- Click on "SDKs" under "Platform Settings" and look at the "Documentation Paths" tab.
Add the following paths (the path may be different based on which JDK you're using):
Add the following path under the Sourcepath tab:
Thanks, @Yishai for the download location and @Gareth Davis for the location of the documentation after installing.