| TaxonomyVersion | 2018 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2017-11 | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedReferences | true | http://fasb.org/srt/role/changeNote/changeNote |
| Publisher | FASB | http://www.xbrl.org/2003/role/disclosureRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2003/role/disclosureRef |
| Topic | 932 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 235 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 50 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 33 | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447 | http://www.xbrl.org/2003/role/disclosureRef |
| Publisher | FASB | http://www.xbrl.org/2003/role/disclosureRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2003/role/disclosureRef |
| Topic | 932 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 235 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 50 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 31 | http://www.xbrl.org/2003/role/disclosureRef |
| Subparagraph | (b) | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=68064819&loc=d3e62455-109447 | http://www.xbrl.org/2003/role/disclosureRef |
| Publisher | SEC | http://www.xbrl.org/2003/role/disclosureRef |
| Name | Form 20-F | http://www.xbrl.org/2003/role/disclosureRef |
| Section | Item 18 | http://www.xbrl.org/2003/role/disclosureRef |
| Subsection | Instruction 2 | http://www.xbrl.org/2003/role/disclosureRef |
| Publisher | FASB | http://www.xbrl.org/2003/role/exampleRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2003/role/exampleRef |
| Topic | 932 | http://www.xbrl.org/2003/role/exampleRef |
| SubTopic | 235 | http://www.xbrl.org/2003/role/exampleRef |
| Section | 55 | http://www.xbrl.org/2003/role/exampleRef |
| Paragraph | 6 | http://www.xbrl.org/2003/role/exampleRef |
| URI | http://asc.fasb.org/extlink&oid=34713648&loc=d3e63094-109448 | http://www.xbrl.org/2003/role/exampleRef |