Segment Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2019 USD ($) state region	Mar. 31, 2018 USD ($)	Mar. 31, 2019 USD ($) state region segment	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)
Segment Reporting [Abstract]
Number of states in which home building segments operate \| state	13		13
Number of regions in which entity operates \| region	3		3
Number of homebuilding segments \| segment			3
Segment Reporting Information [Line Items]
Revenue	$ 421,260	$ 455,178	$ 823,300	$ 827,667
Operating income	(138,950)	13,825	(135,444)	20,506
Depreciation and amortization	2,900	3,066	5,670	5,573
Capital Expenditures			11,508	8,192
Assets	2,055,341		2,055,341		$ 2,128,102
Operating Segments
Segment Reporting Information [Line Items]
Operating income	(92,765)	48,538	(61,729)	83,954
Depreciation and amortization	2,541	2,790	4,967	5,064
Corporate and unallocated
Segment Reporting Information [Line Items]
Operating income	(46,185)	(34,713)	(73,715)	(63,448)
Depreciation and amortization	359	276	703	509
Capital Expenditures			2,829	1,636
Assets	580,032		580,032		542,713
West Segment
Segment Reporting Information [Line Items]
Revenue	210,430	234,510	419,374	412,481
West Segment \| Operating Segments
Segment Reporting Information [Line Items]
Operating income	(107,018)	31,715	(82,757)	52,825
Depreciation and amortization	1,263	1,697	2,541	2,953
Capital Expenditures			5,338	4,238
Assets	758,627		758,627		835,230
East Segment
Segment Reporting Information [Line Items]
Revenue	94,066	107,412	182,812	196,265
East Segment \| Operating Segments
Segment Reporting Information [Line Items]
Operating income	6,929	8,926	12,324	16,322
Depreciation and amortization	547	551	1,085	990
Capital Expenditures			1,286	1,133
Assets	315,728		315,728		335,474
Southeast Segment
Segment Reporting Information [Line Items]
Revenue	116,764	113,256	221,114	218,921
Southeast Segment \| Operating Segments
Segment Reporting Information [Line Items]
Operating income	7,324	7,897	8,704	14,807
Depreciation and amortization	731	$ 542	1,341	1,121
Capital Expenditures			2,055	$ 1,185
Assets	$ 400,954		$ 400,954		$ 414,685

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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