I was just perusing the plugin repository for IntelliJ IDEA plugins recently and came across the FindBugs plugin. It will analyze your code and give you a categorized list of potential problems in your code that links to the source. It bundles the latest FindBugs implementation so there is no need to download that as well.
It looks promising for catching things I may have missed in my code.
There is currently a bug where when you first use it, you need to go into the settings for FindBugs and click on Restore Defaults. That initializes the list of detectors that it uses.
http://findbugs.sourceforge.net - the findbugs home page
https://findbugs-idea.dev.java.net - the findbugs IntelliJ IDEA home page
http://www.jetbrains.com/idea - the IntelliJ IDEA home page