| elementCreationTaxonomyVersion | 2012 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |
| SourceName | Disclosure Framework-Fair Value | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2019 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2018-10 | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedDocumentation | true | http://fasb.org/srt/role/changeNote/changeNote |
| PreviousDocumentation | Estimate remaining period the underlying assets are expected to be liquidated by the investees for investments for which net asset value per share is calculated (including by unit, membership interest, or other ownership interest unit measure), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. | http://fasb.org/srt/role/changeNote/changeNote |
| Source_ASU_Number | 2018-13 | 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 | 820 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 10 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 50 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 6A | http://www.xbrl.org/2003/role/disclosureRef |
| Subparagraph | (b) | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=123874694&loc=SL6742756-110258 | http://www.xbrl.org/2003/role/disclosureRef |