Fair Value Measurements Fair Value of Financial Instrument Assumptions (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Fair Value of Financial Instrument Assumptions [Line Items]
Assets Held-for-sale, Not Part of Disposal Group		$ 5,600,000
Impairment Charge on Reclassified Assets	$ 0.000	$ 0
Revolving Credit Facility [Member]
Fair Value of Financial Instrument Assumptions [Line Items]
Basis Point Spread on Variable Rate	2.50%
Line of Credit Facility, Maximum Borrowing Capacity	$ 500,000,000
Line of Credit Facility, Initiation Date	Jul. 18, 2013
Warehousing Agreement - Third Amendment to Second Amended and Restated [Member]
Fair Value of Financial Instrument Assumptions [Line Items]
Basis Point Spread on Variable Rate	2.00%
Line of Credit Facility, Maximum Borrowing Capacity	$ 125,000,000
Line of Credit Facility, Initiation Date	Jun. 24, 2016
Repurchase Agreement -Second Amendment to Second Amended and Restated [Member]
Fair Value of Financial Instrument Assumptions [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 65,000,000
Line of Credit Facility, Initiation Date	Oct. 30, 2017

[Line Items] for Fair Value of Financial Instrument Assumptions [Table]

No definition available.

Name:	mho_FairValueofFinancialInstrumentAssumptionsLineItems
Namespace Prefix:	mho_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of assets held-for-sale that are not part of a disposal group.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=77912953&loc=d3e400-110220

+ Details

Name:	us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

For the asset that is reclassified back to held and used from held-for-sale, the amount of impairment charge that is recognized on the reclassification date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 44
-URI http://asc.fasb.org/extlink&oid=29634951&loc=d3e1756-110224

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2459-110228

+ Details

Name:	us-gaap_ImpairmentChargeOnReclassifiedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date the credit facility first became available, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=mho_WarehousingAgreementThirdAmendmenttoSecondAmendedandRestatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=mho_RepurchaseAgreementSecondAmendmenttoSecondAmendedandRestatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: