Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 185,120	$ 152,052	$ 157,312	$ 129,163	$ 137,424	$ 114,342	$ 105,750	$ 100,734	$ 623,647	$ 458,250	$ 390,985
Gross profit	36,988	31,004	35,070	27,268	28,997	25,506	23,031	21,500	130,330	99,034	87,762
Net income attributable to Green Brick Partners, Inc.	$ 13,354	$ 12,197	$ 14,869	$ 11,203	$ (8,195)	$ 9,279	$ 7,689	$ 6,197	$ 51,623	$ 14,970	$ 23,756
Net income attributable to Green Brick Partners, Inc. per common share: (2)
Earnings Per Share, Basic	$ 0.26	$ 0.24	$ 0.29	$ 0.22	$ (0.16)	$ 0.19	$ 0.16	$ 0.13	$ 1.02	$ 0.30	$ 0.49
Earnings Per Share, Diluted	$ 0.26	$ 0.24	$ 0.29	$ 0.22	$ (0.16)	$ 0.19	$ 0.16	$ 0.13	$ 1.02	$ 0.30	$ 0.49