Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	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. Our operating results for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for any future periods.
Principles of Consolidation	Principles of Consolidation The Company evaluates its wholly-owned subsidiaries and controlled builders under ASC 810, Consolidation (“ASC 810”). The Company owns a 50% equity interest and has 51% of the voting interest in the Dallas and Atlanta based controlled builders. The Company accounts for the Dallas and Atlanta based controlled builders under the variable interest model and is the primary beneficiary of each of these controlled builders in accordance with ASC 810. Therefore, the financial statements of these controlled builders are consolidated in the condensed consolidated financial statements. The Company recently acquired an 80% controlling interest in GRBK GHO Homes, LLC (“GHO Homes”) and therefore is required to consolidate 100% of GHO Homes within its consolidated financial statements. The 20% interest which the Company does not own is accounted for as a redeemable noncontrolling interest. All intercompany balances and transactions with wholly-owned subsidiaries and controlled builders have been eliminated in consolidation. The Company uses the equity method of accounting for its investment 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.
Receivables	Receivables Receivables consist of amounts collectible from manufacturing rebates earned by our homebuilders during the normal course of business, amounts collectible from third-party escrow agents related to closings on land, lot and residential unit sales, and amounts collectible related to mechanics lien contracts, as well as income tax receivables.
Variable Interest Entities and Noncontrolling Interests	Variable Interest Entities and Noncontrolling Interests The Company accounts for variable interest entities (“VIEs”) in accordance with ASC 810. In accordance with ASC 810, an entity is a VIE when: (a) the equity investment at risk in the entity is not sufficient to permit the entity to finance its activities without additional subordinated financial support provided by other parties, including the equity holders; (b) the entity’s equity holders as a group either (i) lack the direct or indirect ability to make decisions about the entity, (ii) are not obligated to absorb expected losses of the entity, or (iii) do not have the right to receive expected residual returns of the entity; or (c) the entity’s equity holders have voting rights that are not proportionate to their economic interests and the activities of the entity involve or are conducted on behalf of the equity holder with disproportionately few voting rights. If an entity is deemed to be a VIE pursuant to ASC 810, the enterprise that has both (i) the power to direct the activities of the VIE that most significantly impacts the entity’s economic performance and (ii) the obligation to absorb the expected losses of the entity or right to receive benefits from the entity that could be potentially significant to the VIE is considered the primary beneficiary and must consolidate the VIE. In accordance with ASC 810, the Company performs ongoing reassessments of whether it is the primary beneficiary of a VIE.
Investment in Unconsolidated Entities	Investment in Unconsolidated Entities The Company uses the equity method of accounting for its investment in consolidated entities over which it exercises significant influence but does not have a controlling interest.
Debt Issuance Costs	Debt Issuance Costs Debt issuance costs represent costs incurred related to the revolving and unsecured credit facilities, including amendments thereto, and reduce the carrying amount of debt on the condensed consolidated balance sheets. These costs are capitalized to inventory over the term of the related debt facility using the straight-line method.
Segment Information	Segment Information In accordance with ASC 280, Segment Reporting (“ASC 280”), an operating segment is defined as a component of an enterprise for which discrete financial information is available and reviewed regularly by the chief operating decision maker (“CODM”), or decision-making group, to evaluate performance and make operating decisions. The Company identifies its CODM as four key executives—the Chief Executive Officer, Chief Financial Officer, President of Texas Region and Chief Accounting Officer. In determining the most appropriate reportable segments, the CODM considers similar economic and other characteristics, including geography, class of customers, product types and production processes. The Company’s operations are organized into two reportable segments: builder operations and land development. Builder operations consists of three operating segments: Texas, Georgia and Florida. The operations of the Company’s controlled builders were aggregated into these operating segments based on similar (1) economic characteristics, including geography; (2) housing products; (3) class of homebuyer; (4) regulatory environments; and (5) methods used to construct and sell homes. Corporate operations are reported as a non-operating segment and include activities which support the Company’s builder operations, land development and title operations through centralization of certain administrative functions such as finance, treasury, information technology and human resources, as well as development of strategic initiatives. Unallocated corporate expenses are reported in the corporate and other segment as these activities do not share a majority of aggregation criteria with either the builder operations or land development segments. While Green Brick Title, LLC (“Green Brick Title”) operations are not economically similar to either builder operations or land development, the results of such operations do not meet the quantitative thresholds, as discussed in ASC 280, to be separately reported and disclosed. As such, Green Brick Title’s results are included within the corporate and other segment. While the operations of Challenger Homes meet the criteria for an operating segment within the builder operations segment, such operations did not meet the quantitative thresholds, as discussed in ASC 280, to be separately reported and disclosed. As such, Challenger Homes’ results are included within the corporate and other segment.
Business Combinations	Business Combinations Acquisitions are accounted for in accordance with ASC 805, Business Combinations (“ASC 805”). In connection with our acquisition of GHO Homes, we determined that we obtained control of a business and inputs, processes and outputs in exchange for cash. All material assets and liabilities, including contingent consideration, will be measured and recognized at fair value as of the date of the acquisition to reflect the purchase price, which is expected to result in goodwill. A preliminary allocation of the purchase price has been completed as of June 30, 2018. Refer to Note 2 for further information regarding the purchase price allocation and related acquisition accounting.
Goodwill	Goodwill The excess of the purchase price of a business acquisition over the net fair value of assets acquired and liabilities assumed is capitalized as goodwill in accordance with ASC 805. Goodwill is assessed for impairment at least annually, or more frequently if certain impairment indicators are present. We perform our annual impairment test during the fourth quarter or whenever impairment indicators are present.
Intangible Assets	Intangible Assets Intangible assets, net consists of the estimated fair value of home construction contracts that were acquired upon closing of the acquisition of GHO Homes. A high degree of judgment is made by management on assumptions, such as revenue growth rates, profitability, and discount rates, when calculating the value of the intangible assets.
Recent Accounting Pronouncements	Recent Accounting Pronouncements The Company adopted Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, on January 1, 2018 (“ASU 2014-09”). ASU 2014-09 was codified into ASC 606, Revenue from Contracts with Customers (“ASC 606”). The Company adopted ASC 606 using the modified retrospective method applied to contracts which were not completed as of January 1, 2018, which required the cumulative effect of the initial application of the new standard, if any, to be reflected as an adjustment to the opening balance of retained earnings as of January 1, 2018. The Company’s revenue recognition disclosures expanded significantly under ASC 606, specifically related to the quantitative and qualitative information about performance obligations, information about contract balances, changes in contract assets and liabilities and disaggregation of revenue. The adoption of ASC 606 did not have a material effect on the Company’s condensed consolidated statements of income and there was no cumulative effect on the opening balance of retained earnings as of January 1, 2018. As a result of the adoption of ASU 2014-09, costs related to model home furnishings are no longer capitalizable as inventory; however, such costs are capitalizable as fixed assets. As of June 30, 2018, $1.8 million of model home furnishings costs were included in property and equipment, net compared to $1.1 million included in inventory as of December 31, 2017. The related depreciation expense of $0.8 million is included in selling, general and administrative expense for the six months ended June 30, 2018 as opposed to $0.5 million included in cost of sales for the six months ended June 30, 2017. See Note 5. The adoption of ASU 2014-09 did not require significant changes to the Company's internal controls and procedures over financial reporting and disclosures. However, we have made enhancements to existing internal controls and procedures to ensure continued compliance with the disclosure requirements of the new standard. In February 2016, the FASB issued ASU 2016-02, Leases, which requires an entity that leases assets to classify the leases as either finance or operating leases and to record assets and liabilities for the rights and obligations created by long-term leases, regardless of the lease classification. The lease classification will determine whether the lease expense is recognized based on an effective interest rate method or on a straight-line basis over the term of the lease. This standard is effective for the Company beginning January 1, 2019 and must be adopted using a modified retrospective approach. The Company does not believe that the adoption of this standard will have a material effect on its consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which reduces the existing diversity in practice in financial reporting across all industries by clarifying certain existing principles including providing additional guidance on what an entity should consider in determining the classification of certain cash receipts and payments. This standard was adopted by the Company as of January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The standard provides a more robust framework for determining whether transactions should be accounted for as acquisitions or dispositions of assets or businesses. This standard was effective for the Company beginning January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements and related disclosures. In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), which amends the scope of modification accounting for share-based payment arrangements. The standard provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASU 2017-09. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. This standard was effective for the Company beginning January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements and related disclosures.
Reclassifications	Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation.