Inventory and Capitalized Interest Other Inventory Items - Homes under construction not subject to a sale contract (Details) $ in Millions	Sep. 30, 2016 USD ($) homes	Dec. 31, 2015 USD ($)
Other Inventory, Gross [Abstract]
Number of Speculative Homes	973	872
Speculative Homes Carrying Value	$ 179.7	$ 184.3