| Increase (decrease) in provision for bonuses for directors (and other officers) | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Increase (decrease) in provision for bonuses for directors (and other officers) - OpeCF | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| 役員賞与引当金の増減額(△は減少) | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 役員賞与引当金の増減額(△は減少)、営業活動によるキャッシュ・フロー | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |