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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income attributable to Green Brick Partners, Inc.	$ 33,647	$ 14,460	$ 49,564	$ 27,065
Weighted-average number of shares outstanding —basic (in shares)	50,583	50,655	50,519	50,609
Basic net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.67	$ 0.29	$ 0.98	$ 0.53
Dilutive effect of stock options and restricted stock awards (in shares)			150	56
Weighted-average number of shares outstanding —diluted (in shares)	50,692	50,724	50,669	50,665
Diluted net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 0.66	$ 0.29	$ 0.98	$ 0.53