Debt MIF Warehousing Agreement (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Debt Instrument [Line Items]
Maximum Borrowing Availability under all Credit Lines	$ 125,000	$ 150,000
Notes payable bank - financial service operations	87,186	$ 123,648
Warehousing Agreement - Fourth Amendment to Amended and Restated [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity under MIF Warehousing Line	110,000
Optional increase in borrowing availability	20,000
M/I Financial Temporary Increase Maximum Borrowing Capacity	130,000
Aggreate Maximum Principal Amount Permitted to be Outstanding Under All Warehousing Credit Lines	$ 150,000
LIBOR basis points	250
Debt Instrument, Basis Spread on Variable Rate	2.75%
Repurchase Agreement [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity under MIF Warehousing Line	$ 15,000
Minimum [Member] | Amendment No. 1 to Amended and Restated Repurchase Agreement [Member]
Debt Instrument [Line Items]
LIBOR basis points	250
Maximum [Member] | Amendment No. 1 to Amended and Restated Repurchase Agreement [Member]
Debt Instrument [Line Items]
LIBOR basis points	275