| Income arising from exchanges of goods or services, interest | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Concept not required due to removal of IAS 18 | en | http://www.xbrl.org/2009/role/deprecatedLabel | http://www.xbrl.org/2003/role/link |
| 2018-01-01 | en | http://www.xbrl.org/2009/role/deprecatedDateLabel | http://www.xbrl.org/2003/role/link |
| The amount of income arising from the exchanges of goods or services related to interest. | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |