<div class="container">
    <div class="row">
        <!--left-->
        <div class="col-sm-3">
        </div>
        <!--/left-->

        <!--center-->
        <div class="col-sm-6">
        </div>
        <!--/center-->

        <!--right-->
        <div class="col-sm-3">
        </div>
        <!--/right-->
    </div>
</div>
<!-- /.container -->

<div id="page">
    <div class="col" id="left">Content</div>
    <div class="col" id="middle">Content</div>
    <div class="col" id="right">Content</div>
</div>


* {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
#page {
    display: table;
    width: 100%;
}
    #page .col {
        display: table-cell;
        vertical-align: top;
        padding: 20px;
    }
    #left {
        width: 150px;
        background: #777
    }
    #middle {
        width: auto;
        background: #aaa;
    }
    #right {
        width: 345px;
        background: #ccc;
    }