Supplemental Guarantor Information - Consolidating Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Total revenue	$ 781,701	$ 482,738	$ 421,260	$ 402,040	$ 767,945	$ 511,521	$ 455,178	$ 372,489	$ 2,087,739	$ 2,107,133	$ 1,916,278
Home construction and land sales expenses									1,773,085	1,755,619	1,600,969
Inventory impairments and abandonments	0	0	147,611	1,007	6,331	168	0	0	148,618	6,499	2,445
Gross profit	116,297	71,764	(82,680)	60,655	125,865	83,244	75,077	60,829	166,036	345,015	312,864
Commissions									79,802	81,002	74,811
General and administrative expenses									161,371	168,658	161,906
Depreciation and amortization									14,759	13,807	14,009
Operating (loss) income	36,005	9,543	(138,950)	3,506	43,462	17,580	13,825	6,681	(89,896)	81,548	62,138
Equity in income of unconsolidated entities									404	34	371
Gain (Loss) on extinguishment of debt	(25,494)	358	216	0	(1,935)	0	0	(25,904)	(24,920)	(27,839)	(12,630)
Other (expense) income, net									(2,226)	(4,305)	(15,230)
(Loss) income from continuing operations before income taxes									(116,638)	49,438	34,649
(Benefit) expense from income taxes									(37,217)	94,484	2,696
Equity in income of subsidiaries									0	0	0
(Loss) income from continuing operations	$ 2,464	$ 11,625	$ (100,832)	$ 7,322	$ 60,484	$ 13,429	$ 11,616	$ (130,575)	(79,421)	(45,046)	31,953
Loss from discontinued operations, net of tax									(99)	(329)	(140)
Equity in loss of subsidiaries from discontinued operations									0	0	0
Net (loss) income									(79,520)	(45,375)	31,813
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Total revenue									(115)	(83)	(107)
Home construction and land sales expenses									(115)	(83)	(107)
Inventory impairments and abandonments									0	0	0
Gross profit									0	0	0
Commissions									0	0	0
General and administrative expenses									0	0	0
Depreciation and amortization									0	0	0
Operating (loss) income									0	0	0
Equity in income of unconsolidated entities									0	0	0
Gain (Loss) on extinguishment of debt									0	0	0
Other (expense) income, net									0	0	0
(Loss) income from continuing operations before income taxes									0	0	0
(Benefit) expense from income taxes									0	0	0
Equity in income of subsidiaries									(40,788)	12,505	(106,474)
(Loss) income from continuing operations									(40,788)	12,505	(106,474)
Loss from discontinued operations, net of tax									0	0	0
Equity in loss of subsidiaries from discontinued operations									99	329	140
Net (loss) income									(40,689)	12,834	(106,334)
Beazer Homes USA, Inc.
Condensed Financial Statements, Captions [Line Items]
Total revenue									0	0	0
Home construction and land sales expenses									93,875	91,132	88,764
Inventory impairments and abandonments									13,908	1,961	56
Gross profit									(107,783)	(93,093)	(88,820)
Commissions									0	0	0
General and administrative expenses									0	0	0
Depreciation and amortization									0	0	0
Operating (loss) income									(107,783)	(93,093)	(88,820)
Equity in income of unconsolidated entities									0	0	0
Gain (Loss) on extinguishment of debt									(24,920)	(27,839)	(12,630)
Other (expense) income, net									(3,109)	(5,323)	(15,635)
(Loss) income from continuing operations before income taxes									(135,812)	(126,255)	(117,085)
(Benefit) expense from income taxes									(15,603)	(93,714)	(42,564)
Equity in income of subsidiaries									40,788	(12,505)	106,474
(Loss) income from continuing operations									(79,421)	(45,046)	31,953
Loss from discontinued operations, net of tax									0	0	0
Equity in loss of subsidiaries from discontinued operations									(99)	(329)	(140)
Net (loss) income									(79,520)	(45,375)	31,813
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total revenue									2,087,739	2,107,133	1,916,278
Home construction and land sales expenses									1,679,325	1,664,570	1,512,312
Inventory impairments and abandonments									134,710	4,538	2,389
Gross profit									273,704	438,025	401,577
Commissions									79,802	81,002	74,811
General and administrative expenses									161,375	168,536	161,804
Depreciation and amortization									14,759	13,807	14,009
Operating (loss) income									17,768	174,680	150,953
Equity in income of unconsolidated entities									404	34	371
Gain (Loss) on extinguishment of debt									0	0	0
Other (expense) income, net									887	1,046	429
(Loss) income from continuing operations before income taxes									19,059	175,760	151,753
(Benefit) expense from income taxes									(21,643)	188,217	45,266
Equity in income of subsidiaries									0	0	0
(Loss) income from continuing operations									40,702	(12,457)	106,487
Loss from discontinued operations, net of tax									(85)	(312)	(115)
Equity in loss of subsidiaries from discontinued operations									0	0	0
Net (loss) income									40,617	(12,769)	106,372
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total revenue									115	83	107
Home construction and land sales expenses									0	0	0
Inventory impairments and abandonments									0	0	0
Gross profit									115	83	107
Commissions									0	0	0
General and administrative expenses									(4)	122	102
Depreciation and amortization									0	0	0
Operating (loss) income									119	(39)	5
Equity in income of unconsolidated entities									0	0	0
Gain (Loss) on extinguishment of debt									0	0	0
Other (expense) income, net									(4)	(28)	(24)
(Loss) income from continuing operations before income taxes									115	(67)	(19)
(Benefit) expense from income taxes									29	(19)	(6)
Equity in income of subsidiaries									0	0	0
(Loss) income from continuing operations									86	(48)	(13)
Loss from discontinued operations, net of tax									(14)	(17)	(25)
Equity in loss of subsidiaries from discontinued operations									0	0	0
Net (loss) income									$ 72	$ (65)	$ (38)