| SourceName | Steamship | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2018 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2017-12 | http://fasb.org/srt/role/changeNote/changeNote |
| NewElement | true | http://fasb.org/srt/role/changeNote/changeNote |
| Source_ASU_Number | 2017-15 | 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 | 740 | http://www.xbrl.org/2003/role/disclosureRef |
| SubTopic | 10 | http://www.xbrl.org/2003/role/disclosureRef |
| Section | 65 | http://www.xbrl.org/2003/role/disclosureRef |
| Paragraph | 6 | http://www.xbrl.org/2003/role/disclosureRef |
| Subparagraph | (b) | http://www.xbrl.org/2003/role/disclosureRef |
| URI | http://asc.fasb.org/extlink&oid=120432090&loc=SL115996081-158277 | http://www.xbrl.org/2003/role/disclosureRef |