<div class="scalable-container">
<?php
echo CHtml::dropDownList(
    'RoutingOutbound[' . $data->id . '][usergroup]', $data->targetType . '_' . $data->usergroup, $listData, array(
    'class' => 'scalable',
    'data-translation-target' => 'ROUTINGOUTBOUND_MODEL_USERGROUP_TARGET'
));
?>
</div>