2 Column Floating Div Same Height CSS Solution

markup

<div class="row two-col">
  <div class="col-xs-6 col-sm-2">
    <img src="https://s3-us-west-1.amazonaws.com/airenvyassets/return_key.png" class="img-responsive" />
  </div>
  <div class="col-xs-6 col-sm-10 contrast-box">
    <span>Don't forget to return the key!</span>
    1) $50 fee for unreturned keys <br />
    2) Checkouts after 11AM are charged $50/hr
  </div>
</div>

styles

div.two-col {
  display: table;
  div {
    float: none;
    display: table-cell;
    vertical-align: bottom;
  }
}