Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Common Stock, Shares, Issued	50,879,949	50,719,884	50,879,949	50,719,884	50,879,949	50,719,884	50,719,884	50,598,901
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			50,583,128
Beginning balance	$ 498,643	$ 455,532	$ 485,632	$ 433,038
Ending balance (in shares)	50,488,010		50,488,010
Ending balance	$ 516,493	470,194	$ 516,493	470,194
Common stock, $0.01 par value: 100,000,000 shares authorized; 50,879,949 and 50,719,884 issued and 50,488,010 and 50,583,128 outstanding as of September 30, 2019 and December 31, 2018, respectively	$ 509	$ 507	$ 509	$ 507	$ 509	$ 507	$ 507	$ 506
Treasury Stock, Common, Shares	(391,939)	0	(391,939)	0	(183,938)	(136,756)	0	0
Treasury Stock, Value	$ (3,167)	$ 0	$ (3,167)	$ 0	$ (1,369)	$ (981)	$ 0	$ 0
Additional Paid in Capital	291,111	291,007	291,111	291,007	289,739	291,299	290,842	289,938
Retained Earnings (Accumulated Deficit)	220,262	164,172	220,262	164,172	204,591	177,526	151,975	125,903
Stockholders' Equity Attributable to Parent	508,715	455,686	508,715	455,686	493,470	468,351	443,324	416,347
APIC, Share-based Payment Arrangement, Option, Increase for Cost Recognition	73	72	$ 215	$ 215
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			219,181	140,211
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture			$ 1,466	$ 1,081
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(59,116)	(39,228)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation			$ (544)	$ (412)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	$ 136	104	$ 354	$ 301
Treasury Stock, Shares, Acquired	(208,001)		(255,183)	0
Treasury Stock, Value, Acquired, Cost Method	$ (1,798)		$ (2,186)	$ 0
Stockholders' Equity Attributable to Noncontrolling Interest	7,778	14,508	7,778	14,508	$ 5,173	$ 17,281	$ 12,208	$ 16,691
Payments to Noncontrolling Interests			10,993	10,746
Stock Issued During Period, Value, Acquisitions			0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders		(323)	(10,993)	(10,746)
Net income attributable to Green Brick Partners, Inc.	15,671	12,197	42,736	38,269
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	2,605	2,623	1,490	8,563
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	18,276	14,820	44,226	46,832
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture			3	1
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation			1	0
Additional Paid-in Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture			1,463	1,080
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation			(543)	412
Temporary Equity, Accretion to Redemption Value, Adjustment	$ 1,163	$ (11)	$ (1,677)	$ (115)