| Name | InterestOnlyStripMember |
|---|---|
| Namespace | http://fasb.org/us-gaap/2020-01-31 |
| Prefix | us-gaap |
| Data type | nonnum:domainItemType |
| Period type | duration |
| Substitution Group | xbrli:item |
| Balance | None |
| Nillable | True |
| Abstract | True |
| Text | Lang | Role | Container role |
|---|---|---|---|
| Tranche of a securitization that entitles the holder to receive some or all of the interest collected on the underlying mortgages comprising the securitization; a significant risk is prepayment speed greater than the assumption upon which purchase price was based. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Interest-Only-Strip [Member] | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |