Net Income Attributable to Green Brick Partners, Inc. Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to Green Brick Partners, Inc.	$ 15,671	$ 12,197	$ 42,736	$ 38,269
Weighted-average number of shares outstanding —basic (in shares)	50,475	50,686	50,564	50,642
Basic net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.31	$ 0.24	$ 0.85	$ 0.76
Dilutive effect of stock options and restricted stock awards (in shares)	122	92	78	118
Weighted-average number of shares outstanding —diluted (in shares)	50,597	50,778	50,642	50,760
Diluted net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.31	$ 0.24	$ 0.84	$ 0.75