It is a stuck dropdown. If you make your browser smaller, it will turn into an actual dropdown. It looks like someone heard about responsive design, but didn't really understand why or how.
It's actually not bad - it's likely too complex to make it responsive all the way down to mobile, and they have a mobile site for that function, but it fits perfectly for those browsing on different screens.
I just wish they'd make it fixed width. The site's barren on my wide monitor.
I just wish they'd make it fixed width. The site's barren on my wide monitor.