| 商品有価証券収益 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 商品有価証券収益、経常収益、銀行業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| (うち商品有価証券収益) | ja | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |
| Net gain on trading securities | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Net gain on trading securities - OI - BNK | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Net gain on trading securities | en | http://disclosure.edinet-fsa.go.jp/jppfs/bnk/role/label | http://www.xbrl.org/2003/role/link |