| SourceName | Retirement Benefits:Taxonomy Technical Improvement | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2018 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2017-08 | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedDocumentation | true | http://fasb.org/srt/role/changeNote/changeNote |
| PreviousDocumentation | Amount of future annual benefits of participant covered by insurance contract. Includes, but is not limited to, contract issued by employer or its related parties. | http://fasb.org/srt/role/changeNote/changeNote |
| Publisher | FASB | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| Name | Accounting Standards Codification | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| Topic | 715 | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| SubTopic | 20 | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| Section | 50 | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| Paragraph | 1 | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| Subparagraph | (n) | http://fasb.org/us-gaap/role/ref/otherTransitionRef |
| URI | http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 | http://fasb.org/us-gaap/role/ref/otherTransitionRef |