Bootstrap 3.1 Dropdown overlapped by panel

dropdown menu's are being overlapped by the panel-collapse container

by feus4177

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.0/css/bootstrap.min.css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.0/js/bootstrap.min.js"></script>
<button type="button" class="btn btn-primary" data-target="#collapseTableOne">Collapse 1</button>
<button type="button" class="btn btn-primary" data-target="#collapseTableTwo">Collapse 2</button>
<button type="button" class="btn btn-primary" data-target="#collapseTableThree">Collapse 3</button>
<div class="panel-group">
    <div class="panel panel-default">
        <div class="panel-heading hover-link" data-toggle="collapse" data-parent="false" data-target="#collapseTableOne">
             <h4 class="panel-title">
            Collapsible Table Group Item #1
          </h4>

        </div>
        <div id="collapseTableOne" class="panel-collapse collapse">
            <div class="panel-body">
                <table class="table table-striped table-condensed table-hover">
                    <thead>
                        <tr>
                            <th>
                                <input type="checkbox">
                            </th>
                            <th>ID</th>
                            <th>First Name</th>
                            <th>Last Name</th>
                            <th>Username</th>
                            <th></th>
                        </tr>
                    </thead>
                    <tbody>
                        <tr>
                            <td>
                                <input type="checkbox">
                            </td>
                            <td>0521</td>
                            <td>Frank</td>
                            <td>Jackson</td>
                            <td>fjackson</td>
                            <td class="text-right">
                                <div class="dropdown"> <a data-toggle="dropdown" href="#">Actions</a>

                                    <ul class="dropdown-menu...

JavaScript

$('.btn').click(function () {
    var target = $(this).data('target');
    $(target).collapse('hide');
});