Contingencies - Warranty (Details) $ in Thousands	3 Months Ended		39 Months Ended
	Dec. 31, 2017 USD ($) home	Dec. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) home
Loss Contingencies [Line Items]
Standard product warranty length, minimum	1 year
Standard product warranty length, maximum	2 years
Limited product warranty length (up to)	10 years
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 18,091	$ 39,131
Accruals for warranties issued	4,212	2,658
Changes in liability related to warranties existing in prior periods	(2,296)	5,392
Payments made	(4,191)	(14,872)
Balance at end of period	15,816	32,309	$ 15,816
Insurance recoveries	(200)	3,900	82,800
Specific Warranty Issue
Movement in Standard Product Warranty Accrual [Roll Forward]
Product warranty expense			85,200
Specific Warranty Issue | Florida
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at end of period	3,200		$ 3,200
Product warranty expense	$ (400)	$ 4,600
Homes likely to require more than minor repairs | home	709		709
Homes have been repaired | home	664		664
Product warranty accrual, payments	$ 1,100
Estimated remaining warranty costs	$ 2,500		$ 2,500