Segment Information (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2020 USD ($) state segment region	Dec. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)
Segment Reporting [Abstract]
Number of states in which home building segments operate | state	13
Number of regions in which entity operates | region	3
Number of reportable segments | segment	3
Segment Reporting Information [Line Items]
Revenue	$ 428,539	$ 417,804
Operating income	17,688	3,946
Depreciation and amortization	3,122	3,427
Capital expenditures	2,953	2,632
Assets	1,984,474		$ 2,007,480
Operating Segments
Segment Reporting Information [Line Items]
Operating income	54,979	38,808
Depreciation and amortization	2,603	2,902
Corporate and unallocated
Segment Reporting Information [Line Items]
Operating income	(37,291)	(34,862)
Depreciation and amortization	519	525
Capital expenditures	649	180
Assets	692,766		779,694
West Segment
Segment Reporting Information [Line Items]
Revenue	236,880	254,398
West Segment | Operating Segments
Segment Reporting Information [Line Items]
Operating income	33,303	30,331
Depreciation and amortization	1,537	1,808
Capital expenditures	1,636	1,484
Assets	673,605		658,909
East Segment
Segment Reporting Information [Line Items]
Revenue	97,964	78,040
East Segment | Operating Segments
Segment Reporting Information [Line Items]
Operating income	11,368	5,321
Depreciation and amortization	471	554
Capital expenditures	434	452
Assets	305,980		267,050
Southeast Segment
Segment Reporting Information [Line Items]
Revenue	93,695	85,366
Southeast Segment | Operating Segments
Segment Reporting Information [Line Items]
Operating income	10,308	3,156
Depreciation and amortization	595	540
Capital expenditures	234	$ 516
Assets	$ 312,123		$ 301,827