Inventory and Capitalized Interest Other Inventory Items - Homes under construction not subject to a sale contract (Details) $ in Thousands	Sep. 30, 2018 USD ($) homes	Dec. 31, 2017 USD ($)
Other Inventory, Gross [Abstract]
Number of Speculative Homes	1,436	1,134
Speculative Homes Carrying Value	$ 296,400	$ 242,700
Community development district	$ 16,101	$ 13,049

A CDD is a unit of local government created to allow for the construction and maintenance of long-term infrastructure through alternative financing sources. CDDs may utilize bond financing to fund construction or acquisition of certain on-site and off-site infrastructure improvements near or within a community.

No definition available.

Name:	mho_CommunityDevelopmentDistrict
Namespace Prefix:	mho_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant