Stop Javascript from rounding large numeric identifiers

The following window is issued with a warning: 211466719468855300. Why does this happen even when I try to pass it to a String? How can I read it for sure?

HTML:

<a class="delete-link" data-id="211466719468855298">Delete</a>​

JS:

$('.delete-link').click(function(e) {
        var $item =$(this);
        var itemID = String($item.data('id'));
        alert(itemID);
});

Fiddle: http://jsfiddle.net/zUbym/1/