| Arrangements involving legal form of lease [member] | 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 |
| This member stands for all arrangements involving legal forms of lease. For example, an entity may lease assets to an investor and lease the same assets back, or alternatively, legally sell assets and lease the same assets back. The form of each arrangement and its terms and conditions can vary significantly. It also represents the standard value for the 'Arrangements involving legal form of lease' axis if no other member is used. | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
Index