| その他事業利益又はその他事業損失(△) | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| その他事業利益又はその他事業損失(△)、海運業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| その他事業利益 | ja | http://www.xbrl.org/2003/role/positiveLabel | http://www.xbrl.org/2003/role/link |
| その他事業損失(△) | ja | http://www.xbrl.org/2003/role/negativeLabel | http://www.xbrl.org/2003/role/link |
| Other business profit (loss) | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Other business profit (loss) - WAT | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Other business profit | en | http://www.xbrl.org/2003/role/positiveLabel | http://www.xbrl.org/2003/role/link |
| Other business loss | en | http://www.xbrl.org/2003/role/negativeLabel | http://www.xbrl.org/2003/role/link |