Business Segments Business Segments - Textuals (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended			48 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Jan. 01, 2019
Segment Reporting Information [Line Items]
Purchase Accounting Adjustments		$ 100	$ 100	$ 400	$ 600	$ 700	$ 3,000	$ 900
Charges related to stucco-related claims					1,000				$ 0	$ 0	$ 8,500	$ 28,400
Total valuation adjustments and write-offs	$ 5,000				5,800				5,000	5,800	7,700
Assets Held-for-sale, Not Part of Disposal Group					5,600					5,600		5,600
Operating Lease, Right-of-Use Asset	$ 18,415				$ 0				18,415	0		$ 0	$ 20,900
Northern Homebuilding [Member]
Segment Reporting Information [Line Items]
Purchase Accounting Adjustments									$ 600	$ 5,100
Southern Homebuilding [Member]
Segment Reporting Information [Line Items]
Charges related to stucco-related claims											$ 8,500