I'm using multiple displays (InDesign CC 2014, Mac Yosemite). I want my documents on the large display. I can move documents there, but whenever I click with the cursor or pointer within the document the window moves downwards and only half the document is now visible. That's a problem.
Try centering the Displays in System Preferences.
There are several conversations about this already. Look around.
Bottom line is that this seems to be a bug introduced with the 10.10.2 Yosemite update.