Commitments and Contingencies Commitments and Contingencies (Details) $ in Millions	Mar. 31, 2020 USD ($)
Commitments and Contingencies [Abstract]
Letters of credit and completion bonds	$ 237.8
Performance bonds outstanding	165.8
Performance letters of credit outstanding	52.2
Financial letters of credit	13.7
Financial letters of credit representing deposits on land and lot purchase agreements	13.2
Financial Bonds	6.1
Unrecorded conditional purchase obligation	$ 720.9