CSS - parent div is not expanding to width/height of child

Question

I am looking to overlay a caption on to an image. I have managed to do this, but the image is expanding out of the parent div.

I have the containing div set to inline-block, as I want it to 'auto size', not take up width: 100%. If you look at the current output, you'll see the image could be within the black bordered box.

It only needs to work in Chrome, if you encounter cross-browser issues.

Thanks in advance!

LIVE DEMO

---

CSS:

#body_content {
    border: solid 1px blue;
    display: inline-block;    
    padding: 5px;
}
#body_header {
    border: solid 1px red;
    font-size: 25px;
    padding: 5px;
}
#body_image {
    position: absolute;
}
#body_image_caption {
    color: white;
    line-height: 30px;
    margin-left: 10px;
}
#body_image_container {
    background: white;
    border: solid 1px black;
    margin-top: 3px;
    padding: 10px;
}
#body_image_overlay {
    background-color: black;
    bottom: 5px;
    display: block;
    height: 30px;
    opacity: 0.85;
    position: absolute;
    width: 100%;    
}​

HTML:

<div id="body_content">
   <div id="body_header">
      Heading
   </div>
   <div id="body_image_container">
      <div id="body_image">
          <img src="http://i.imgur.com/s6G8n.jpg" width="200" height="200" />
          <div id="body_image_overlay">
             <div id="body_image_caption">
                Some Text
             </div>
          </div>
      </div>
   </div>
</div>

Answer 1

The #body_image element is escaping from the #body_image_container because its position is set to absolute. Absolutely positioned elements are removed from the document's flow, causing parent elements to collapse as though the child element wasn't there. If you change it to relative, then it becomes contained within the black box:

#body_image{
    position: relative;
}

http://jsfiddle.net/AaXTm/2/