| 一般管理費 | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 一般管理費、海運業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| 一般管理費合計 | ja | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| General and administrative expenses | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| General and administrative expenses-WAT | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Total general and administrative expenses | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |