Basis of Presentation	3 Months Ended
Mar. 31, 2017
Basis of Presentation [Abstract]
Basis of Accounting [Text Block]	Basis of Presentation The accompanying Unaudited Condensed Consolidated Financial Statements (the “financial statements”) of M/I Homes, Inc. and its subsidiaries (the “Company”) and notes thereto have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information. The financial statements include the accounts of the Company. All intercompany transactions have been eliminated. Results for the interim period are not necessarily indicative of results for a full year. In the opinion of management, the accompanying financial statements reflect all adjustments (all of which are normal and recurring in nature) necessary for a fair presentation of financial results for the interim periods presented. These financial statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the “2016 Form 10-K”). The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during that period. Actual results could differ from these estimates and have a significant impact on the financial condition and results of operations and cash flows. With regard to the Company, estimates and assumptions are inherent in calculations relating to valuation of inventory and investment in unconsolidated joint ventures, property and equipment depreciation, valuation of derivative financial instruments, accounts payable on inventory, accruals for costs to complete inventory, accruals for warranty claims, accruals for self-insured general liability claims, litigation, accruals for health care and workers’ compensation, accruals for guaranteed or indemnified loans, stock-based compensation expense, income taxes, and contingencies. Items that could have a significant impact on these estimates and assumptions include the risks and uncertainties listed in “Item 1A. Risk Factors” in Part I of our 2016 Form 10-K, as the same may be updated from time to time in our subsequent filings with the SEC. Reclassifications Certain financial statement line items reflected on the March 31, 2016 Statement of Cash Flows were affected by the Company’s early adoption of Accounting Standards Update (“ASU”) No. 2016-18, Statement of Cash Flows: Restricted Cash (“ASU 2016-18”) during the fourth quarter of 2016 as a result of the change in accounting principle. Recently Adopted Accounting Standards In March 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”). ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences and classification on the statement of cash flows. For public entities, ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. The Company adopted the new standard in the first quarter of 2017. Excess tax benefits or deficiencies for stock-based compensation are now reflected in the Condensed Consolidated Statements of Income as a component of income tax expense, whereas previously they were recognized in equity. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and disclosures. Impact of New Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which provides guidance for revenue recognition. ASU 2014-09 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets and supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and most industry-specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, “Revenue Recognition-Construction-Type and Production-Type Contracts.” ASU 2014-09’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under today’s guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date, which delayed the effective date of ASU 2014-09 by one year. ASU 2014-09, as amended, is effective for public companies for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Early adoption is permitted as of the original effective date for annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. Subsequent to the issuance of ASU 2014-09, the FASB has issued several ASUs, such as ASU 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ASU 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing, and ASU 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients. These ASUs do not change the core principle of the guidance stated in ASU 2014-09. Instead, these amendments are intended to clarify and improve the operability of certain topics addressed by ASU 2014-09. These additional ASUs will have the same effective date and transition requirements as ASU 2014-09, as amended. See below for additional explanation of each of these additional ASUs. The Company does not believe the adoption of these additional ASUs will not have a material impact on our consolidated financial statements. The guidance in ASU 2014-09 permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the cumulative catch-up transition method). The new standard is effective for our fiscal year beginning January 1, 2018, and, at that time, we currently anticipate adopting the standard using the cumulative catch-up transition method. We anticipate this standard will not have a material impact on our consolidated financial statements. While we are continuing to assess all potential impacts of the standard, and have been involved in industry-specific discussions with the FASB on the treatment of certain items, we currently believe the most significant impact could relate to our accounting for sale of land and/or lots to third parties that have continuing performance obligations. We expect the amount and timing of our homebuilding revenue to remain substantially unchanged. Due to the complexity of certain of our land contracts, however, the actual revenue recognition treatment required under the standard for land sales will depend on contract-specific terms, and may vary in some instances from recognition at the time of closing. We are continuing to evaluate the impact the adoption of ASU 2014-09 may have on other aspects of our business and on our consolidated financial statements and disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 will require organizations that lease assets - referred to as “lessees” - to recognize on the balance sheet the assets and liabilities for the rights and obligations created by those leases. Under ASU 2016-02, a lessee will be required to recognize assets and liabilities for leases with lease terms of more than 12 months. Lessor accounting remains substantially similar to current GAAP. In addition, disclosures of leasing activities will expand to include qualitative and specific quantitative information. For public entities, ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-02 mandates a modified retrospective transition method. The Company is currently evaluating the potential impact the adoption of ASU 2016-02 will have on the Company’s consolidated financial statements and disclosures. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (“ASU 2016-08”). The amendments in this ASU are intended to improve the operability and understandability of the implementation guidance stated in ASU 2014-09 on principal versus agent considerations and whether an entity reports revenue on a gross or net basis. In April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing (“ASU 2016-10”). ASU 2016-10 provides guidance on identifying performance obligations and licensing. This update clarifies the guidance in ASU 2014-09 relating to identifying performance obligations and licensing. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers: Narrow Scope Improvements and Practical Expedients (“ASU 2016-12”). ASU 2016-12 provides for amendments to ASU 2014-09 regarding transition, collectability, noncash consideration, and presentation of sales tax and other similar taxes. Specifically, ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all or substantially all of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard’s contract criteria. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 provides guidance on how certain cash receipts and cash payments are to be presented and classified in the statement of cash flows. For public entities, ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The adoption of ASU 2016-15 will modify the Company's current disclosures and reclassifications within the condensed consolidated statement of cash flows but is not expected to have a material effect on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”), which provides a more robust framework for determining whether transactions should be accounted for as acquisitions (or dispositions) of assets or businesses. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is currently evaluating the potential impact the adoption of ASU 2017-01 will have on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test in order to simplify the subsequent measurement of goodwill. The guidance is effective for fiscal years beginning after December 15, 2019. Early application is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not believe the adoption of ASU 2017-04 will have a material impact on the Company’s consolidated financial statements and disclosures. In February 2017, the FASB issued ASU 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”). ASU 2017-05 is intended to clarify the scope of the original guidance within Subtopic 610-20 that was issued in connection with ASU 2014-09, which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with noncustomers. ASU 2017-05 additionally added guidance for partial sales of nonfinancial assets. ASU 2017-05 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. We are required to adopt ASU 2017-05 concurrent with the adoption of ASU 2014-09. The Company is currently evaluating the potential impact the adoption of ASU 2017-05 will have on the Company’s consolidated financial statements and disclosures. In March 2017, the FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities (“ASU 2017-08”), which shortens the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, ASU 2017-08 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company does not believe the adoption of ASU 2017-08 will have a material impact on the Company’s consolidated financial statements and disclosures.

Basis of Presentation

The accompanying Unaudited Condensed Consolidated Financial Statements (the “financial statements”) of M/I Homes, Inc. and its subsidiaries (the “Company”) and notes thereto have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information. The financial statements include the accounts of the Company. All intercompany transactions have been eliminated. Results for the interim period are not necessarily indicative of results for a full year. In the opinion of management, the accompanying financial statements reflect all adjustments (all of which are normal and recurring in nature) necessary for a fair presentation of financial results for the interim periods presented. These financial statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the “2016 Form 10-K”).

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during that period. Actual results could differ from these estimates and have a significant impact on the financial condition and results of operations and cash flows. With regard to the Company, estimates and assumptions are inherent in calculations relating to valuation of inventory and investment in unconsolidated joint ventures, property and equipment depreciation, valuation of derivative financial instruments, accounts payable on inventory, accruals for costs to complete inventory, accruals for warranty claims, accruals for self-insured general liability claims, litigation, accruals for health care and workers’ compensation, accruals for guaranteed or indemnified loans, stock-based compensation expense, income taxes, and contingencies. Items that could have a significant impact on these estimates and assumptions include the risks and uncertainties listed in “Item 1A. Risk Factors” in Part I of our 2016 Form 10-K, as the same may be updated from time to time in our subsequent filings with the SEC.

Reclassifications

Certain financial statement line items reflected on the March 31, 2016 Statement of Cash Flows were affected by the Company’s early adoption of Accounting Standards Update (“ASU”) No. 2016-18, Statement of Cash Flows: Restricted Cash (“ASU 2016-18”) during the fourth quarter of 2016 as a result of the change in accounting principle.

Recently Adopted Accounting Standards

In March 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”). ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences and classification on the statement of cash flows. For public entities, ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. The Company adopted the new standard in the first quarter of 2017. Excess tax benefits or deficiencies for stock-based compensation are now reflected in the Condensed Consolidated Statements of Income as a component of income tax expense, whereas previously they were recognized in equity. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and disclosures.

Impact of New Accounting Standards

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which provides guidance for revenue recognition. ASU 2014-09 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets and supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and most industry-specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, “Revenue Recognition-Construction-Type and Production-Type Contracts.” ASU 2014-09’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under today’s guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date, which delayed the effective date of ASU 2014-09 by one year. ASU 2014-09, as amended, is effective for public companies for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Early adoption is permitted as of the original effective date for annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period.

Subsequent to the issuance of ASU 2014-09, the FASB has issued several ASUs, such as ASU 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ASU 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing, and ASU 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients. These ASUs do not change the core principle of the guidance stated in ASU 2014-09. Instead, these amendments are intended to clarify and improve the operability of certain topics addressed by ASU 2014-09. These additional ASUs will have the same effective date and transition requirements as ASU 2014-09, as amended. See below for additional explanation of each of these additional ASUs. The Company does not believe the adoption of these additional ASUs will not have a material impact on our consolidated financial statements.

The guidance in ASU 2014-09 permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the cumulative catch-up transition method). The new standard is effective for our fiscal year beginning January 1, 2018, and, at that time, we currently anticipate adopting the standard using the cumulative catch-up transition method.

We anticipate this standard will not have a material impact on our consolidated financial statements. While we are continuing to assess all potential impacts of the standard, and have been involved in industry-specific discussions with the FASB on the treatment of certain items, we currently believe the most significant impact could relate to our accounting for sale of land and/or lots to third parties that have continuing performance obligations. We expect the amount and timing of our homebuilding revenue to remain substantially unchanged. Due to the complexity of certain of our land contracts, however, the actual revenue recognition treatment required under the standard for land sales will depend on contract-specific terms, and may vary in some instances from recognition at the time of closing. We are continuing to evaluate the impact the adoption of ASU 2014-09 may have on other aspects of our business and on our consolidated financial statements and disclosures.

In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 will require organizations that lease assets - referred to as “lessees” - to recognize on the balance sheet the assets and liabilities for the rights and obligations created by those leases. Under ASU 2016-02, a lessee will be required to recognize assets and liabilities for leases with lease terms of more than 12 months. Lessor accounting remains substantially similar to current GAAP. In addition, disclosures of leasing activities will expand to include qualitative and specific quantitative information. For public entities, ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-02 mandates a modified retrospective transition method. The Company is currently evaluating the potential impact the adoption of ASU 2016-02 will have on the Company’s consolidated financial statements and disclosures.

In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (“ASU 2016-08”). The amendments in this ASU are intended to improve the operability and understandability of the implementation guidance stated in ASU 2014-09 on principal versus agent considerations and whether an entity reports revenue on a gross or net basis.

In April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing (“ASU 2016-10”). ASU 2016-10 provides guidance on identifying performance obligations and licensing. This update clarifies the guidance in ASU 2014-09 relating to identifying performance obligations and licensing.

In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers: Narrow Scope Improvements and Practical Expedients (“ASU 2016-12”). ASU 2016-12 provides for amendments to ASU 2014-09 regarding transition, collectability, noncash consideration, and presentation of sales tax and other similar taxes. Specifically, ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all or substantially all of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard’s contract criteria.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 provides guidance on how certain cash receipts and cash payments are to be presented and classified in the statement of cash flows. For public entities, ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The adoption of ASU 2016-15 will modify the Company's current disclosures and reclassifications within the condensed consolidated statement of cash flows but is not expected to have a material effect on the Company’s consolidated financial statements and disclosures.

In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”), which provides a more robust framework for determining whether transactions should be accounted for as acquisitions (or dispositions) of assets or businesses. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is currently evaluating the potential impact the adoption of ASU 2017-01 will have on the Company’s consolidated financial statements and disclosures.

In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test in order to simplify the subsequent measurement of goodwill. The guidance is effective for fiscal years beginning after December 15, 2019. Early application is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not believe the adoption of ASU 2017-04 will have a material impact on the Company’s consolidated financial statements and disclosures.

In February 2017, the FASB issued ASU 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”). ASU 2017-05 is intended to clarify the scope of the original guidance within Subtopic 610-20 that was issued in connection with ASU 2014-09, which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with noncustomers. ASU 2017-05 additionally added guidance for partial sales of nonfinancial assets. ASU 2017-05 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. We are required to adopt ASU 2017-05 concurrent with the adoption of ASU 2014-09. The Company is currently evaluating the potential impact the adoption of ASU 2017-05 will have on the Company’s consolidated financial statements and disclosures.

In March 2017, the FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities (“ASU 2017-08”), which shortens the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, ASU 2017-08 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company does not believe the adoption of ASU 2017-08 will have a material impact on the Company’s consolidated financial statements and disclosures.