Unique ID not Generated

Looking at adding a unique ID to various service div's of one page, that I can add to a URL to link to and jump to the respective div i.e. service.html#events1

I've added a shared region that uses a template, html below. I've added the function to create a unique ID on the first div but the output doesn't include the ID, html output is <div id="serv" class="service">

The offending function HTML:

<div id="serv<perch:content id="perch_item_index" type="hidden">" class="service">

Full template html:

<div id="serv<perch:content id="perch_item_index" type="hidden">" class="service">
<div class="col-xs-12 col-sm-12">
<h2><perch:content id="service_name" type="text" label="Name" required="true" title="true" /></h2>
</div>

<div class="col-xs-12 col-sm-3">
<img src="<perch:content type="image" id="service_image_large" label="Square Service Image" />" alt="Taylor Harley financial services, <perch:content type="text" id="service_name" />" class="img-responsive hidden-xs visible-sm visible-md visible-lg" />
<img src="<perch:content type="image" id="service_image_small" label="Rectangular Service Image" />" alt="Taylor Harley financial services, <perch:content type="text" id="service_name" />" class="img-responsive visible-xs hidden-sm hidden-md hidden-lg" />
</div>

<div class="col-xs-12 col-sm-9">
<perch:content id="service_description" type="textarea" label="Service Description" markdown="true" editor="simplemde" required="true" />
<div class="example">
<h3><perch:content id="service_example_title" type="text" label="Panel Text Title" /></h3>
<p><perch:content id="service_example" type="textarea" label="Panel Text" markdown="true" editor="simplemde" /></p>
</div>

<a href="contact_taylor_hartley.php" title="contact Taylor Hartley today" class="btn btn-default">Contact us <span class="hidden-sm hidden-xs"><strong>TODAY</strong> </span>for a free <span class="hidden-xs">inital </span>consultation <span class="glyphicon glyphicon-play" aria-hidden="true"></span></a>
</div>
</div>

Any insight greatly appreciated