| PublishDate | 2018-01 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |
| Source | Taxonomy Implementation Guide | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |
| SourceName | Retirement Benefits-Phase 2 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |
| pdfURI | https://www.fasb.org/retirementbenefitsphase2_2020 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |
| SourceName | Reference Project:Taxonomy Technical Improvement | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2020 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2019-11 | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedReferences | true | http://fasb.org/srt/role/changeNote/changeNote |
| SourceName | Retirement Benefits:Taxonomy Technical Improvement | http://fasb.org/srt/role/changeNote/changeNote |
| 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/2009/role/commonPracticeRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2009/role/commonPracticeRef |
| Topic | 850 | http://www.xbrl.org/2009/role/commonPracticeRef |
| SubTopic | 10 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Section | 50 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Paragraph | 3 | http://www.xbrl.org/2009/role/commonPracticeRef |
| URI | http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Publisher | FASB | http://www.xbrl.org/2009/role/commonPracticeRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2009/role/commonPracticeRef |
| Topic | 850 | http://www.xbrl.org/2009/role/commonPracticeRef |
| SubTopic | 10 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Section | 50 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Paragraph | 1 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Subparagraph | (c) | http://www.xbrl.org/2009/role/commonPracticeRef |
| URI | http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Publisher | FASB | http://www.xbrl.org/2009/role/commonPracticeRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2009/role/commonPracticeRef |
| Topic | 715 | http://www.xbrl.org/2009/role/commonPracticeRef |
| SubTopic | 20 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Section | 50 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Paragraph | 1 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Subparagraph | (n) | http://www.xbrl.org/2009/role/commonPracticeRef |
| URI | http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Publisher | FASB | http://www.xbrl.org/2009/role/commonPracticeRef |
| Name | Accounting Standards Codification | http://www.xbrl.org/2009/role/commonPracticeRef |
| Topic | 850 | http://www.xbrl.org/2009/role/commonPracticeRef |
| SubTopic | 10 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Section | 50 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Paragraph | 1 | http://www.xbrl.org/2009/role/commonPracticeRef |
| Subparagraph | (d) | http://www.xbrl.org/2009/role/commonPracticeRef |
| URI | http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 | http://www.xbrl.org/2009/role/commonPracticeRef |