<?php $departamento = ""; foreach($salidas AS $rowS): ?>

    <?php if ($departamento != $rowS['nombreDepartamento']): $departamento = $rowS['nombreDepartamento'];?>

        <h4>DEPARTAMENTO: <?=$departamento?></h4>

            <table style="width: 100%;" border="1" cellpadding="3">
                <thead>
                    <tr>
                        <th>Fecha</th>
                        <th>Departamento</th>
                        <th>Doc</th>
                        <th>Numero</th>
                        <th>Orden</th>
                        <th>Subtotal</th>
                        <th>Descuento</th>
                        <th>Itbis</th>
                        <th>Total</th>
                    </tr>
                </thead>
                <tbody>

    <?php endif; ?>

        <tr>
            <td><?=$rowS['fecha']?></td>
            <td><?=$rowS['nombreDepartamento']?></td>
            <td><?=$rowS['documento']?></td>
            <td><?=$rowS['numero']?></td>
            <td><?=$rowS['orden']?></td>
            <td><?=$rowS['bruto']?></td>
            <td><?=$rowS['tdesc']?></td>
            <td><?=$rowS['itbis']?></td>
            <td><?=$rowS['neto']?></td>
        </tr>

    <?php if ($departamento != $rowS['nombreDepartamento']): ?>

        </tbody>
        </table>
        <hr>
    <?php endif; ?>

<?php  endforeach; ?>