Site Hierarchy
Site Hierarchy is very important to inform users of layout relationships. Your show details button to me is not not very well connected to the extra detail it reveals. When going through your prototype I have to click this button really fast to find out what was actually changing because you moved the layouts to accommodate for the extra detail.
Recommendation
I would recommend to keep the button closer to the area in which the content will change. make the content change underneath the button, not above. As a user I have already skimmed and memorized this area, for you to change it on me builds a bit of a cognitive overload.
Execution
As per execution, your giving the same weight (site hierarchy) to the details button as your are the reports. I would argue that details is not a primary call to action, as such this should be presented differently to the user.
From what I see there was enough from for this information as is. Perhaps if your doing this to reduce cognitive load, allow the user to dig deep into data by using a tooltip (unless this is going to be used on tablets or phones).
Option (Not necessarily the best)