Contingencies - Warranty (Details) $ in Thousands	3 Months Ended		27 Months Ended
	Dec. 31, 2016 USD ($) home	Dec. 31, 2015 USD ($)	Dec. 31, 2016 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	$ 39,131	$ 27,681
Accruals for warranties issued	2,658	2,615
Changes in liability related to warranties existing in prior periods	5,392	10,600
Payments made	(14,872)	(11,983)
Balance at end of period	32,309	28,913	$ 32,309
Insurance recoveries	3,900	13,700
Excess insurance recovery		3,600
Specific Warranty Issue | Florida
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	22,600
Balance at end of period	17,200		17,200
Product warranty expense	$ 4,600	$ 9,000	$ 83,200
Homes likely to require more than minor repairs | home	705		705
Movement on number of homes likely to be repaired | home	16
Homes have been repaired | home	510		510
Product warranty accrual, payments	$ 10,000
Estimated remaining warranty costs	$ 4,200		$ 4,200