The gray footer ribbon at the bottom of my site never stays completly at the bottom

The gray footer ribbon at the bottom of my site never stays completly at the bottom. It tends to float a couple of inches above the bottom of the page. Here is an example for you to see: http://cantridenaked.com/site/about/

I think the theme would look better if the ribbon stayed consistantly at the bottom. Can we do this

 

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

.content_wrapper {
min-height: 500px;
}