This was working a few weeks ago. I'm not sure if this is on my end, or an issue with the software. When I click on a function or method, hit ctrl-Q to bring up Quick Documentation, it doesn't appear that the Quick Documentation dialog is recognizing my docstrings as reStructuredText. What it does render is plain text, and all the parameters are missing. This is in PyCharm 2016.1.2.
I downloaded the latest PyCharm release candidate 145.969.10, but still getting the same behavior. I also removed my PyCharm 2016 settings in my c:\users\<username> so that PyCharm would regenerate to default settings. In both versions, I ensure the following settings (see image), but still no luck. I removed settings again, and imported my settings from PyCharm 5 which does properly render the docstrings, and 2016.1.2 is still not rendering them proerply.
I've been beating my head on this, and lost way too much time. All works fine in PyCharm 5 which is what I'm falling back on.