Debt	3 Months Ended
Debt	Mar. 31, 2020
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt Notes Payable - Homebuilding The Credit Facility provides an aggregate commitment amount of $500 million, including a $125 million sub-facility for letters of credit. The Credit Facility expires on July 18, 2021. Interest on amounts borrowed under the Credit Facility is payable at a rate which is adjusted daily and is equal to the sum of the one-month LIBOR rate plus a margin of 250 basis points. The margin is subject to adjustment in subsequent quarterly periods based on the Company’s leverage ratio. The Credit Facility also contains certain financial covenants. At March 31, 2020, the Company was in compliance with all financial covenants of the Credit Facility. The available amount under the Credit Facility is computed in accordance with a borrowing base, which is calculated by applying various advance rates for different categories of inventory, and totaled $626.6 million of availability for additional senior debt at March 31, 2020. As a result, the full $500 million commitment amount of the Credit Facility was available, less any borrowings and letters of credit outstanding. At March 31, 2020, there were $6.9 million of borrowings outstanding and $65.8 million of letters of credit outstanding, leaving net remaining borrowing availability of $427.3 million. The Company’s obligations under the Credit Facility are guaranteed by all of the Company’s subsidiaries, with the exception of subsidiaries that are primarily engaged in the business of mortgage financing, title insurance or similar financial businesses relating to the homebuilding and home sales business, certain subsidiaries that are not 100%-owned by the Company or another subsidiary, and other subsidiaries designated by the Company as Unrestricted Subsidiaries (as defined in Note 12 to our financial statements), subject to limitations on the aggregate amount invested in such Unrestricted Subsidiaries in accordance with the terms of the Credit Facility and the indentures for the Company’s $400.0 million aggregate principal amount of 4.95% Senior Notes due 2028 (the “2028 Senior Notes”) and the Company’s $250.0 million aggregate principal amount of 5.625% Senior Notes due 2025 (the “2025 Senior Notes”). The guarantors for the Credit Facility (the “Guarantor Subsidiaries”) are the same subsidiaries that guarantee the 2028 Senior Notes and the 2025 Senior Notes. The Company’s obligations under the Credit Facility are general, unsecured senior obligations of the Company and the Guarantor Subsidiaries and rank equally in right of payment with all our and the Guarantor Subsidiaries’ existing and future unsecured senior indebtedness. Our obligations under the Credit Facility are effectively subordinated to our and the Guarantor Subsidiaries’ existing and future secured indebtedness with respect to any assets comprising security or collateral for such indebtedness. Notes Payable — Financial Services The MIF Mortgage Warehousing Agreement is used to finance eligible residential mortgage loans originated by M/I Financial. The MIF Mortgage Warehousing Agreement provides for a maximum borrowing availability of $125 million, which increased to $160 million from September 25, 2019 to October 15, 2019 and from November 15, 2019 to February 4, 2020 (periods of increased volume of mortgage originations). The MIF Mortgage Warehousing Agreement expires on June 19, 2020. Interest on amounts borrowed under the MIF Mortgage Warehousing Agreement is payable at a per annum rate equal to the floating LIBOR rate plus a spread of 200 basis points. The MIF Mortgage Warehousing Agreement also contains certain financial covenants. At March 31, 2020, M/I Financial was in compliance with all financial covenants of the MIF Mortgage Warehousing Agreement. The MIF Mortgage Repurchase Facility is used to finance eligible residential mortgage loans originated by M/I Financial. The MIF Repurchase Facility provides for a mortgage repurchase facility with a maximum borrowing availability of $65 million. The MIF Mortgage Repurchase Facility expires on October 26, 2020. M/I Financial pays interest on each advance under the MIF Mortgage Repurchase Facility at a per annum rate equal to the floating LIBOR rate plus 175 or 200 basis points depending on the loan type. The MIF Mortgage Repurchase Facility also contains certain financial covenants. At March 31, 2020, M/I Financial was in compliance with all financial covenants of the MIF Mortgage Repurchase Facility. At March 31, 2020 and December 31, 2019, M/I Financial’s total combined maximum borrowing availability under the two credit facilities was $190.0 million and $225.0 million, respectively. At March 31, 2020 and December 31, 2019, M/I Financial had $145.1 million and $136.9 million outstanding on a combined basis under its credit facilities, respectively. Senior Notes On January 22, 2020, the Company issued $400.0 million aggregate principal amount of the 2028 Senior Notes. The 2028 Senior Notes bear interest at a rate of 4.95% per year, payable semiannually in arrears on February 1 and August 1 of each year (commencing on August 1, 2020), and mature on February 1, 2028. We may redeem all or any portion of the 2028 Senior Notes on or after February 1, 2023 at a stated redemption price, together with accrued and unpaid interest thereon. The redemption price will initially be 103.713% of the principal amount outstanding, but will decline to 102.475% of the principal amount outstanding if redeemed during the 12-month period beginning on February 1, 2024, will further decline to 101.238% of the principal amount outstanding if redeemed during the 12-month period beginning on February 1, 2025 and will further decline to 100.000% of the principal amount outstanding if redeemed on or after February 1, 2026, but prior to maturity. The Company used a portion of the net proceeds from the issuance of the 2028 Senior Notes to redeem all $300 million aggregate principal amount of its then outstanding 6.75% Senior Notes due 2021 (the “2021 Senior Notes”) at 100.000% of the principal amount outstanding, plus accrued and unpaid interest thereon, on January 22, 2020. As of both March 31, 2020 and December 31, 2019, we had $250.0 million of our 2025 Senior Notes outstanding. The 2025 Senior Notes bear interest at a rate of 5.625% per year, payable semiannually in arrears on February 1 and August 1 of each year, and mature on August 1, 2025. We may redeem all or any portion of the 2025 Senior Notes on or after August 1, 2020 at a stated redemption price, together with accrued and unpaid interest thereon. The redemption price will initially be 104.219% of the principal amount outstanding, but will decline to 102.813% of the principal amount outstanding if redeemed during the 12-month period beginning on August 1, 2021, will further decline to 101.406% of the principal amount outstanding if redeemed during the 12-month period beginning on August 1, 2022 and will further decline to 100.000% of the principal amount outstanding if redeemed on or after August 1, 2023, but prior to maturity. The 2028 Senior Notes and the 2025 Senior Notes contain certain covenants, as more fully described and defined in the indenture governing the 2028 Senior Notes and the indenture governing the 2025 Senior Notes, which limit the ability of the Company and the restricted subsidiaries to, among other things: incur additional indebtedness; make certain payments, including dividends, or repurchase any shares, in an aggregate amount exceeding our “restricted payments basket”; make certain investments; and create or incur certain liens, consolidate or merge with or into other companies, or liquidate or sell or transfer all or substantially all of our assets. These covenants are subject to a number of exceptions and qualifications as described in the indenture governing the 2028 Senior Notes and the indenture governing the 2025 Senior Notes. As of March 31, 2020, the Company was in compliance with all terms, conditions, and covenants under the indentures. The 2028 Senior Notes and the 2025 Senior Notes are fully and unconditionally guaranteed jointly and severally on a senior unsecured basis by the Guarantor Subsidiaries. The 2028 Senior Notes and the 2025 Senior Notes are general, unsecured senior obligations of the Company and the Guarantor Subsidiaries and rank equally in right of payment with all our and the Guarantor Subsidiaries’ existing and future unsecured senior indebtedness. The 2028 Senior Notes and the 2025 Senior Notes are effectively subordinated to our and the Guarantor Subsidiaries’ existing and future secured indebtedness with respect to any assets comprising security or collateral for such indebtedness. The indenture governing our 2028 Senior Notes and the indenture governing the 2025 Senior Notes limit our ability to pay dividends on, and repurchase, our common shares and any of our preferred shares then outstanding to the amount of the positive balance in our “restricted payments basket,” as defined in the indentures. In each case, the “restricted payments basket” is equal to $125.0 million plus (1) 50% of our aggregate consolidated net income (or minus 100% of our aggregate consolidated net loss) from October 1, 2015, excluding income or loss from Unrestricted Subsidiaries, plus (2) 100% of the net cash proceeds from either contributions to the common equity of the Company after December 1, 2015 or the sale of qualified equity interests after December 1, 2015, plus other items and subject to other exceptions. The positive balance in our restricted payments basket was $276.3 million at March 31, 2020 and $264.5 million at December 31, 2019. The determination to pay future dividends on, or make future repurchases of, our common shares will be at the discretion of our board of directors and will depend upon our results of operations, financial condition, capital requirements and compliance with debt covenants, and other factors deemed relevant by our board of directors. Notes Payable - Other The Company had other borrowings, which are reported in Notes Payable - Other in our Unaudited Condensed Consolidated Balance Sheets, totaling $7.5 million and $5.8 million as of March 31, 2020 and December 31, 2019, respectively, which are comprised of notes payable acquired in the normal course of business.