Basis of Presentation	9 Months Ended
Sep. 30, 2012
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 M/I Homes, Inc. and its subsidiaries. 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, 2011 (the “2011 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 limited liability companies (“Unconsolidated LLCs”), 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 2011 Form 10-K, as the same may be updated from time to time in our subsequent filings with the SEC. Reclassifications Certain amounts in the Unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2011 have been reclassified to conform to the nine months ended September 30, 2012 presentation. The Company believes these reclassifications are immaterial to the Unaudited Condensed Consolidated Financial Statements. Impact of New Accounting Standards In May 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04: Fair Value Measurement (Topic 820) - Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS ("ASU 2011-04"). ASU 2011-04 provides clarity to the fair value definition in order to achieve greater consistency in fair value measurements and disclosures between United States Generally Accepted Accounting Principles (“U.S. GAAP”) and International Financial Reporting Standards (“IFRS”). Additional disclosures are required regarding transfers of assets between Level 1 and 2 of the fair value hierarchy and expands the fair value disclosure requirements particularly for Level 3 measurements. The Company adopted this standard on January 1, 2012 and the adoption did not have a material impact on the Company's financial condition, results of operations or liquidity. In December 2011, the FASB issued ASU No. 2011-11, “Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities.” The amendments in ASU 2011-11 will enhance disclosures required by U.S. GAAP by requiring additional information about financial and derivative instruments that are either (a) offset in accordance with Section 210-20-45 or Section 815-10-45 or (b) subject to an enforceable master netting arrangement or similar agreement, irrespective of whether they are offset in accordance with Section 210-20-45 or Section 815-10-45. We are required to apply the amendments for annual reporting periods beginning on or after January 1, 2013, and for interim periods within those annual periods. We are to provide the required disclosures retrospectively for all comparative periods presented. The Company does not anticipate that the adoption of this guidance will have a material impact on its consolidated financial statements.

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 M/I Homes, Inc. and its subsidiaries. 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, 2011 (the “2011 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 limited liability companies (“Unconsolidated LLCs”), 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 2011 Form 10-K, as the same may be updated from time to time in our subsequent filings with the SEC.

Reclassifications

Certain amounts in the Unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2011 have been reclassified to conform to the nine months ended September 30, 2012 presentation. The Company believes these reclassifications are immaterial to the Unaudited Condensed Consolidated Financial Statements.

Impact of New Accounting Standards

In May 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04: Fair Value Measurement (Topic 820) - Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRS ("ASU 2011-04"). ASU 2011-04 provides clarity to the fair value definition in order to achieve greater consistency in fair value measurements and disclosures between United States Generally Accepted Accounting Principles (“U.S. GAAP”) and International Financial Reporting Standards (“IFRS”). Additional disclosures are required regarding transfers of assets between Level 1 and 2 of the fair value hierarchy and expands the fair value disclosure requirements particularly for Level 3 measurements. The Company adopted this standard on January 1, 2012 and the adoption did not have a material impact on the Company's financial condition, results of operations or liquidity.

In December 2011, the FASB issued ASU No. 2011-11, “Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities.” The amendments in ASU 2011-11 will enhance disclosures required by U.S. GAAP by requiring additional information about financial and derivative instruments that are either (a) offset in accordance with Section 210-20-45 or Section 815-10-45 or (b) subject to an enforceable master netting arrangement or similar agreement, irrespective of whether they are offset in accordance with Section 210-20-45 or Section 815-10-45. We are required to apply the amendments for annual reporting periods beginning on or after January 1, 2013, and for interim periods within those annual periods. We are to provide the required disclosures retrospectively for all comparative periods presented. The Company does not anticipate that the adoption of this guidance will have a material impact on its consolidated financial statements.