Equity Method Investments in Real Estate Ventures at Fair Value - Summarized Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Equity Method Investments [Line Items]
Net income (loss)	$ 423	$ (627)	$ 1,591	$ (779)
Comstock Holding Companies, Inc. share of net income (loss)			(114)	(9)
Investors X
Schedule of Equity Method Investments [Line Items]
Total revenue	5,078	3,072	12,276	3,072
Direct costs	4,653	3,750	10,915	3,750
Net income (loss)	425	(678)	1,361	(678)
The Hartford
Schedule of Equity Method Investments [Line Items]
Total revenue	2,486		6,544
Direct costs	814		1,966
Other costs	2,366		6,257
Net income (loss)	(694)		(1,679)
Investors X
Schedule of Equity Method Investments [Line Items]
Comstock Holding Companies, Inc. share of net income (loss)	425	$ (678)	1,361	$ (678)
The Hartford
Schedule of Equity Method Investments [Line Items]
Comstock Holding Companies, Inc. share of net income (loss)	$ (17)		$ (42)