Investment in Unconsolidated Entities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	$ 4,593	$ 5,174	$ 8,484	$ 7,739
Investments in unconsolidated entities	50,342		50,342		$ 46,443
GB Challenger, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	3,225	3,805	5,975	5,566
Investments in unconsolidated entities	33,070		33,070		29,488
Green Brick Mortgage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	545	1,371	1,633	2,160
Investments in unconsolidated entities	886		886		1,207
EJB River Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	473	(1)	472	(1)
Investments in unconsolidated entities	5,769		5,769		5,296
GBTM Sendera, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	17
Investments in unconsolidated entities	9,854		9,854		9,846
BHome Mortgage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	333		404
Investments in unconsolidated entities	763		763		$ 606
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	$ 4,593	$ 5,174	$ 8,484	$ 7,739