When inconsistency occurs between data presented from individual group enterprises, causes of the inconsistency cannot be specified easily in a conventional consolidated settlement processing method. In the embodiments of the invention, an XBRL conversion module converts inputted account data into data resulting from synthesis of standard data and extended data by using a mapping table and transmits the converted data to a data separation module. The data separation module separates the standard data and extended data of the received data and stores these types of data in corresponding storage tables while adding them with information for mutual relevancy. In this manner, when inconsistency occurs during a consolidated settlement process, causes of the inconsistency can be specified easily by acquiring the extended data.