Actually, you don't have the latest version of InDesign. You're using InDesign CC 2014. You should be able to download InDesign CC 2015 from the Creative Cloud app since you're running Mac OS X 10.9.x which meets the system requirement. The tool is working for me in InDesign CC 2015.
Be aware that if you install CC 2015, by default it will remove CC 2014 so you may want to read this blog post I wrote about how to keep both versions:
If you don't want to install CC 2015, try restoring your InDesign preferences to see if it fixes the problem:
Ah, right. My apologies, Steve. I meant to say I have the most up-to-date CC 2014 (Our team has chosen to wait to install 2015).
Anyway, I reset my preferences as per the instructions above and no dice. I even rebooted for good measure. Should I maybe try uninstalling and reinstalling ID?
I went back to load InDesign CC 2014, the very same version as you. I'm running Yosemite. No problems.
I'd try uninstalling and reinstalling.
Okay, so I tried that, and I even uninstalled Creative Cloud and started from scratch. Still the same. There must be a corrupted file or preference that's hanging on, even after an uninstall. Frustrating.
I'm having the same issue with the color theme picker. It worked fine until I upgraded to 2015. I trashed my prefs but it didn't help. At first (and now since I trashed my prefs) it doesn't disappear when you start using other tools and eventually (as before) it will only work as an eyedropper and you only get one color.