Net Income Attributable to Green Brick Partners, Inc. Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to Green Brick Partners, Inc.	$ 14,460	$ 14,869	$ 27,065	$ 26,072
Weighted-average number of shares outstanding —basic (in shares)	50,655	50,664	50,609	50,620
Basic net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.29	$ 0.29	$ 0.53	$ 0.52
Dilutive effect of stock options and restricted stock awards (in shares)	69	119	56	131
Weighted-average number of shares outstanding —diluted (in shares)	50,724	50,783	50,665	50,751
Diluted net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.29	$ 0.29	$ 0.53	$ 0.51