| SourceName | Retirement Benefits:Taxonomy Technical Improvement | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2020 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2019-10 | http://fasb.org/srt/role/changeNote/changeNote |
| NewElement | 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 | 715 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 70 | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/subtopic&trid=2235116 | 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 | 715 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 70 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 50 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 1 | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 | http://www.xbrl.org/2003/role/disclosureRef |