| その他事業費用 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| その他事業費用、海運業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| その他事業費用合計 | ja | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Other business expenses | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Other business expenses-WAT | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Total other business expenses | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |