| 借用金利息 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 借用金利息、経常費用、銀行業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| (うち借用金利息) | ja | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |
| Interest on borrowings and rediscounts | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Interest on borrowings and rediscounts-OE-BNK | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Interest on borrowings and rediscounts | en | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |