| 附帯事業営業利益又は附帯事業営業損失(△) | ja | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| 附帯事業営業利益又は附帯事業営業損失(△)、電気通信事業 | ja | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| 附帯事業営業利益 | ja | http://www.xbrl.org/2003/role/positiveLabel | http://www.xbrl.org/2003/role/link |
| 附帯事業営業損失(△) | ja | http://www.xbrl.org/2003/role/negativeLabel | http://www.xbrl.org/2003/role/link |
| Operating profit (loss) from incidental business | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Operating profit (loss) from incidental business - ELC | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Operating profit from incidental business | en | http://www.xbrl.org/2003/role/positiveLabel | http://www.xbrl.org/2003/role/link |
| Operating loss from incidental business | en | http://www.xbrl.org/2003/role/negativeLabel | http://www.xbrl.org/2003/role/link |