Debt MIF Warehousing Agreement (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Maximum Borrowing Availability under all Credit Lines	$ 185,000	$ 150,000
Notes payable bank - financial services operations	152,895	$ 123,648
Warehousing Agreement - Fourth Amendment to Amended and Restated [Member]
Line of Credit Facility [Line Items]
Aggreate Maximum Principal Amount Permitted to be Outstanding Under All Warehousing Credit Lines	150,000
Warehousing Agreement - Second Amended and Restated [Member]
Line of Credit Facility [Line Items]
M/I Financial Maximum Borrowing Capacity	$ 125,000
LIBOR basis points	250
Debt Instrument, Basis Spread on Variable Rate	2.75%
Repurchase Agreement [Member]
Line of Credit Facility [Line Items]
M/I Financial Maximum Borrowing Capacity	$ 15,000
Minimum [Member] | Amendment No. 1 to Amended and Restated Repurchase Agreement [Member]
Line of Credit Facility [Line Items]
LIBOR basis points	250
Maximum [Member] | Amendment No. 1 to Amended and Restated Repurchase Agreement [Member]
Line of Credit Facility [Line Items]
LIBOR basis points	275