Investment in Unconsolidated Entities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	$ 5,555	$ 5,299	$ 14,039	$ 13,038
Investments in unconsolidated entities	52,735		52,735		$ 46,443
GB Challenger, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	4,377	3,825	10,352	9,391
Investments in unconsolidated entities	35,196		35,196		29,488
Green Brick Mortgage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	382	1,498	2,015	3,658
Investments in unconsolidated entities	765		765		1,207
EJB River Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	361		833	(1)
Investments in unconsolidated entities	6,130		6,130		5,296
GBTM Sendera, LLC
Schedule of Equity Method Investments [Line Items]
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	435	(24)	839	(24)
Investments in unconsolidated entities	790		790		$ 606
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	$ 5,555	$ 5,299	$ 14,039	13,038
Providence Group Title, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities				$ 14