Contingencies - Warranty (Details) (USD $)	3 Months Ended			6 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Dec. 31, 2014 home	Sep. 30, 2014 home
Loss Contingencies [Line Items]
Standard product warranty length, minimum	1 year
Standard product warranty length, maximum	2 years
Limited product warranty length	5 years
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 16,084,000	$ 11,663,000			$ 11,663,000
Accruals for warranties issued	1,525,000	1,123,000
Changes in liability related to warranties existing in prior periods	14,230,000	1,743,000
Payments made	(4,612,000)	(2,618,000)
Balance at end of period	27,227,000	11,911,000		27,227,000
Specific Warranty Issue
Movement in Standard Product Warranty Accrual [Roll Forward]
Product warranty expense			4,900,000
FLORIDA
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	4,000,000
Balance at end of period	16,200,000		4,000,000	16,200,000	4,000,000
Homes likely to require more than minor repairs	387				135
Homes repaired during period	42				11
Number of homes requiring more than minor repairs accounted for in warranty liability	345		124	345	124
Product warranty accrual, warranties issued	13,600,000
Product warranty accrual, payments	1,400,000			2,300,000
FLORIDA | Specific Warranty Issue
Movement in Standard Product Warranty Accrual [Roll Forward]
Standard product warranty			8 years
Product warranty expense			4,300,000
NEW JERSEY | Specific Warranty Issue
Movement in Standard Product Warranty Accrual [Roll Forward]
Standard product warranty	8 years
Product warranty expense			$ 600,000
Number of Communities With Water Intrusion Issues	1