Guarantees and Indemnifications Guarantees (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Guarantees [Abstract]
Total of Loans Covered by Guarantees	$ 113.0	$ 21.1
Total of Guaranteed Loans Inquired About	0.9	0.6
Loan Repurchase Guarantee Liability	$ 0.3	$ 0.4

Maximum potential amount of future payments the guarantor could be required to make under the Company's subsidiary loan repurchase guarantees.

No definition available.

Name:	mho_LoanRepurchaseGuaranteeLiability
Namespace Prefix:	mho_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant