Document And Entity Information	12 Months Ended
	Dec. 31, 2020 employee	Feb. 26, 2021 shares	Jun. 30, 2020 USD ($)
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	GRBK
Entity Incorporation, State or Country Code	DE
Document Transition Report	false
Document Quarterly Report	true
Entity Number of Employees | employee	440
Entity Registrant Name	Green Brick Partners, Inc.
Entity Central Index Key	0001373670
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity File Number	001-33530
Entity Tax Identification Number	20-5952523
City Area Code	(469)
Local Phone Number	573-6755
Entity Address, Address Line One	2805 Dallas Pkwy
Entity Address, Address Line Two	Ste 400
Entity Address, City or Town	Plano
Entity Address, Postal Zip Code	75093
Entity Address, State or Province	TX
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Shell Company	false
Entity Public Float | $			$ 283,118,968
Entity Common Stock, Shares Outstanding | shares		50,661,919
Security Exchange Name	NASDAQ
Entity Small Business	true
ICFR Auditor Attestation Flag	true