Commitments and Contingencies Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014
Commitments and Contingencies [Abstract]
Letters of credit and completion bonds	$ 123.6
Performance bonds outstanding	80.4
Performance letters of credit outstanding	14.0
Financial letters of credit	14.2
Financial letters of credit representing deposits on land and lot purchase agreements	7.7
Financial Bonds	15.0
Unrecorded conditional purchase obligation	$ 475.6