| 投資損失引当金繰入額 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 投資損失引当金繰入額、経常費用、銀行業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| (うち投資損失引当金繰入額) | ja | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |
| Provision of allowance for investment loss | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Provision of allowance for investment loss-OE-BNK | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Provision of allowance for investment loss | en | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |