// Show media ID in media library overview
function column_id($columns) {
    $columns['colID'] = __('ID');
    return $columns;
}
add_filter( 'manage_media_columns', 'column_id' );
function column_id_row($columnName, $columnID){
    if($columnName == 'colID'){
       echo $columnID;
    }
}
add_filter( 'manage_media_custom_column', 'column_id_row', 10, 2 );