| Arrangements involving legal form of lease [axis] | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Concept not required as it has an expiry date of 01-01-2019 | en | http://www.xbrl.org/2009/role/deprecatedLabel | http://www.xbrl.org/2003/role/link |
| 2019-01-01 | en | http://www.xbrl.org/2009/role/deprecatedDateLabel | http://www.xbrl.org/2003/role/link |
| The axis of a table defines the relationship between the domain members or categories in the table and the line items or concepts that complete the table. | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |