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