Commitments and Contingencies Legal Liabilities (Details) $ in Millions	3 Months Ended
	Sep. 30, 2016 USD ($) homes	Jun. 30, 2016 USD ($) homes	Dec. 31, 2015 USD ($)
Other Liabilities Disclosure [Abstract]
Product Liability Accrual, Component Amount | $	$ 14.5	$ 4.9	$ 0.5
Estimated Repair Costs for Affected Homes | $	$ 15.1	$ 2.9
Number of Affected Homes | homes	265	178
Additional Number of Affected Homes Associated with Repair Costs | homes	199
Number of Affected Homes on which Repairs Were Resolved | homes	112
Amount Reserved for Legal Expenses | $	$ 0.3		$ 0.6