Commitments and Contingencies Legal Liabilities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Product Liability Accrual, Component Amount						$ 19,400,000	$ 500,000
Charges related to stucco-related claims	$ 0	$ 14,500,000	$ 8,500,000	$ 19,409,000
Estimated Repair Costs for Affected Homes	11,300,000		11,300,000
Amount Reserved for Legal Expenses	400,000		400,000			$ 300,000
General Liability Insurance Deductible	10,000,000		10,000,000		$ 7,500,000
Workers Compensation	$ 250,000		$ 250,000		$ 500,000