Bootstrap create column height same

<html>
<head>
<title>Bootstrap Grid</title>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css">
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
</head>
<style>
.eq-column-height { 
display: -webkit-box;
display: -webkit-flex;
display: -ms-flexbox;
display: flex;	
}
</style>
<body>
<div class="container">
  <div class="row eq-column-height">
  <div class="col-xs-12 col-sm-4 panel" style="background-color: skyblue">
    Column 1
  </div>
  <div class="col-xs-6 col-sm-4 panel" style="background-color: yellow">
	  <div style='height:200px;'>Column 2</div>
  </div>
  <div class="col-xs-6 col-sm-4 panel" style="background-color: gray">
    Column 3
  </div>
</div>
</div>
</body>
</html>