Commitments and Contingencies - Guarantees (Details) - Financial Guarantee $ in Thousands	Sep. 30, 2020 USD ($)
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)	$ 47,780
The Residences at Annapolis Junction
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)	8,300
Delray Plaza
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)	5,180
Interlock Commercial
Commitments and Contingencies
Guarantor obligations, maximum exposure (up to)	$ 34,300

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant