| Weighted average share price for share options in share-based payment arrangement exercised during period at date of exercise | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Concept not required as a result of 2018 annual improvements | 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 weighted average share price at the date of exercise for share options that are exercised in a share-based payment arrangement. [Refer: Share-based payment arrangements [member]; Weighted average [member]] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |