I use sticky footer: http://ryanfait.com/sticky-footer/
/*
Sticky Footer by Ryan Fait
http://ryanfait.com/
*/
* {
margin: 0;
}
html,
body {
height: 100%;
}
.wrapper {
min-height: 100%;
height: auto !important;
height: 100%;
margin: 0 auto -142px;
/* the bottom margin is the negative value of the footer's height */
}
.footer,
.push {
height: 142px;
/* .push must be the same height as .footer */
}
<div class="wrapper">
body goes here
<div class="push"></div>
</div>
<div class="footer">Footer!</div>
Essentially, the wrapper is 100% height, with a negative margin the height of the footer ensuring the footer is always at the bottom without causing scroll.
This should accomplish your goal of having a 100% width footer and narrower body as well, because divs are block level elements, and their width is by default 100% of their parent. Keep in mind the footer here is not contained by the wrapper div.