Can't get sidebar to stretch 100% in height

I’m just starting the code on this. It’s still in basic HTML form, but already I’m having a problem with this.

Here’s the CSS

[ 484 lines of code moderated, that’s just way too much. For that many lines of code please use pastebin.com instead. ]

As you can see I’m trying to make a dashed right border on the sidebar that stretches 100% in height no matter the size of the content. I can get it to stretch if i write the height in pixels, but obviously I don’t want it stuck at that height only.

Hopefully some of you guys can help me out.

Here’s a screenshot:

https://i1164.photobucket.com/albums/q575/mattdelrosario/sidebarborder_zps11369ef8.jpg

Thanks in advance to those who are willing to help out ??