Significant Accounting Policies (Schedule of Basic and Diluted Net Income) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Basic net income attributable to Green Brick Partners, Inc. per share
Net income attributable to Green Brick Partners, Inc. —basic	$ 31,573	$ 3,694	$ 7,410	$ 7,349	$ 8,848	$ 9,513	$ 7,615	$ 6,031	$ 50,026	$ 32,007	$ 17,194
Weighted-average number of shares outstanding - basic (in shares)									14,712	11,109	11,109
Basic net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 1.24	$ 0.33	$ 0.67	$ 0.66	$ 0.79	$ 0.86	$ 0.69	$ 0.54	$ 3.40	$ 2.88	$ 1.55
Diluted net income attributable to Green Brick Partners, Inc. per share
Net income attributable to Green Brick Partners, Inc. —diluted									$ 50,026	$ 32,007	$ 17,194
Weighted-average number of shares outstanding - diluted (in shares)									14,712	11,109	11,109
Diluted net income attributable to Green Brick Partners, Inc. per share (in dollars per share)	$ 1.24	$ 0.33	$ 0.67	$ 0.66	$ 0.79	$ 0.86	$ 0.69	$ 0.54	$ 3.40	$ 2.88	$ 1.55