.footable {
    font-size: 15px;
}

    .footable.breakpoint > tbody > tr > td.expand {
        background: url(../images/plus.png) no-repeat left;
        padding-left: 40px !important;
        background-position-x: 10px;
    }

    .footable.breakpoint > tbody > tr.footable-detail-show > td.expand {
        background: url(../images/minus.png) no-repeat left;
        padding-left: 40px !important;
        background-position-x: 10px;
    }