auto resize sidebar

Good evening all, I am wondering if there is a way to make the sidebar to automatically fit the height of a page as I currently have it fixed at a height of around 2000px. This fits the front page rather well, but when I publish a shorter blogpost I obviously end up will a lot of white space between the end of the post and the footer because the sidebar is set to a fixed height.

I hope that there is a way to make the sidebar ‘liquid’ to that it will fit the page no matter how long the post is.

All the best