| 建設仮勘定 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 建設仮勘定、鉄道事業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| 建設仮勘定合計 | ja | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| 計 | ja | http://disclosure.edinet-fsa.go.jp/jppfs/rwy/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Construction in progress | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Construction in progress-RWY | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Total construction in progress | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Total | en | http://disclosure.edinet-fsa.go.jp/jppfs/rwy/role/totalLabel | http://www.xbrl.org/2003/role/link |