Inventory and Capitalized Interest Other Inventory Items - Homes under construction not subject to a sale contract (Details) $ in Millions	Jun. 30, 2019 USD ($) homes	Dec. 31, 2018 USD ($)
Other Inventory, Gross [Abstract]
Number of Speculative Homes	1,413	1,443
Speculative Homes Carrying Value	$ 264.9	$ 311.0