| 会員勘定 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 会員勘定、銀行業(信金) | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| 会員勘定合計 | ja | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| 会員勘定合計 | ja | http://disclosure.edinet-fsa.go.jp/jppfs/NonConsolidatedInterim/role/totalLabel | http://www.xbrl.org/2003/role/link |
| 会員勘定合計 | ja | http://disclosure.edinet-fsa.go.jp/jppfs/ConsolidatedInterim/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Shareholders' equity | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Shareholders' equity-shinkin-BNK | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Total shareholders' equity | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Total shareholders' equity | en | http://disclosure.edinet-fsa.go.jp/jppfs/NonConsolidatedInterim/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Total shareholders' equity | en | http://disclosure.edinet-fsa.go.jp/jppfs/ConsolidatedInterim/role/totalLabel | http://www.xbrl.org/2003/role/link |