def list_detectors(gd_client, aws_region):
    """
    Lists the detectors in a given Region
    Used to detect if a detector exists already
    :param gd_client: GuardDuty client
    :param aws_region: AWS Region
    :return: Dictionary of AWS_Region: DetectorId
    """

    detector_dict = gd_client.list_detectors()

    if detector_dict['DetectorIds'] == []:
        pass
    else:
        return detector_dict