Organization, Consolidation and Presentation of Financial Statements (Notes)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting [Text Block]	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) as set forth in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) and applicable regulations of the Securities and Exchange Commission (“SEC”), but do not include all of the information and footnotes required for complete financial statements. In the opinion of management, the accompanying condensed consolidated financial statements for the periods presented reflect all adjustments, of a normal, recurring nature necessary to fairly state our financial position, results of operations and cash flows. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2018 or subsequent periods.
Principles of Consolidation	Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of Green Brick Partners, Inc., its controlled subsidiaries, and variable interest entities (“VIEs”) in which Green Brick Partners, Inc. or one of its controlled subsidiaries is deemed to be the primary beneficiary (together, the “Company”, “we”, or “Green Brick”). All intercompany balances and transactions have been eliminated in consolidation.
Equity Method Investments [Policy Text Block]	The Company uses the equity method of accounting for its investments in unconsolidated entities over which it exercises significant influence but does not have a controlling interest. Under the equity method, the Company’s share of the unconsolidated entities' earnings or losses, if any, is included in the condensed consolidated statements of income.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes, including the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates.
Reclassifications	Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation.
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) as set forth in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) and applicable regulations of the Securities and Exchange Commission (“SEC”), but do not include all of the information and footnotes required for complete financial statements. In the opinion of management, the accompanying condensed consolidated financial statements for the periods presented reflect all adjustments, of a normal, recurring nature necessary to fairly state our financial position, results of operations and cash flows. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2018 or subsequent periods. Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of Green Brick Partners, Inc., its controlled subsidiaries, and variable interest entities (“VIEs”) in which Green Brick Partners, Inc. or one of its controlled subsidiaries is deemed to be the primary beneficiary (together, the “Company”, “we”, or “Green Brick”). All intercompany balances and transactions have been eliminated in consolidation. The Company uses the equity method of accounting for its investments in unconsolidated entities over which it exercises significant influence but does not have a controlling interest. Under the equity method, the Company’s share of the unconsolidated entities' earnings or losses, if any, is included in the condensed consolidated statements of income. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes, including the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates. Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation.