Supplemental Guarantor Information - Consolidating Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Total revenue	$ 672,981	$ 478,588	$ 425,468	$ 339,241	$ 632,121	$ 459,937	$ 385,607	$ 344,449	$ 1,916,278	$ 1,822,114	$ 1,627,413
Home construction and land sales expenses									1,600,969	1,509,625	1,351,860
Inventory impairments and abandonments	1,693	470	282	0	184	11,917	1,825	1,356	2,445	15,282	3,109
Gross profit	113,360	78,443	67,398	53,663	102,406	77,653	59,566	57,582	312,864	297,207	272,444
Commissions									74,811	70,460	65,023
General and administrative expenses									161,906	153,628	142,496
Depreciation and amortization									14,009	13,794	13,338
Operating income	37,783	15,569	7,511	1,275	30,838	16,309	3,030	9,148	62,138	59,325	51,587
Equity in income of unconsolidated entities									371	131	536
Loss on extinguishment of debt	2,933	0	(15,563)	0	(11,393)	429	(1,631)	(828)	(12,630)	(13,423)	(80)
Other expense, net									(15,230)	(24,330)	(30,013)
Income from continuing operations before income taxes									34,649	21,703	22,030
Expense (benefit) from income taxes									2,696	16,498	(324,569)
Equity in income of subsidiaries									0	0	0
Income from continuing operations	$ 33,693	$ 7,114	$ (7,495)	$ (1,359)	$ (789)	$ 6,107	$ (1,312)	$ 1,199	31,953	5,205	346,599
Loss from discontinued operations, net of tax									(140)	(512)	(2,505)
Equity in loss of subsidiaries									0	0	0
Net income									31,813	4,693	344,094
Change in unrealized loss related to available-for-sale securities									0	0	1,276
Total Comprehensive Income									31,813	4,693	345,370
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Total revenue									(107)	(156)	(198)
Home construction and land sales expenses									(107)	(156)	(198)
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 income									0	0	0
Equity in income of unconsolidated entities									0	0	0
Loss on extinguishment of debt									0	0	0
Other expense, net									0	0	0
Income from continuing operations before income taxes									0	0	0
Expense (benefit) from income taxes									0	0	0
Equity in income of subsidiaries									(106,474)	(52,541)	(399,162)
Income from continuing operations									(106,474)	(52,541)	(399,162)
Loss from discontinued operations, net of tax									0	0	0
Equity in loss of subsidiaries									140	512	2,505
Net income									(106,334)		(396,657)
Change in unrealized loss related to available-for-sale securities											0
Total Comprehensive Income										(52,029)	(396,657)
Beazer Homes USA, Inc.
Condensed Financial Statements, Captions [Line Items]
Total revenue									0	0	0
Home construction and land sales expenses									88,764	77,941	55,006
Inventory impairments and abandonments									56	710	0
Gross profit									(88,820)	(78,651)	(55,006)
Commissions									0	0	0
General and administrative expenses									0	0	0
Depreciation and amortization									0	0	0
Operating income									(88,820)	(78,651)	(55,006)
Equity in income of unconsolidated entities									0	0	0
Loss on extinguishment of debt									(12,630)	(13,423)	(80)
Other expense, net									(15,635)	(25,388)	(29,752)
Income from continuing operations before income taxes									(117,085)	(117,462)	(84,838)
Expense (benefit) from income taxes									(42,564)	(70,126)	(32,275)
Equity in income of subsidiaries									106,474	52,541	399,162
Income from continuing operations									31,953	5,205	346,599
Loss from discontinued operations, net of tax									0	0	0
Equity in loss of subsidiaries									(140)	(512)	(2,505)
Net income									31,813		344,094
Change in unrealized loss related to available-for-sale securities											1,276
Total Comprehensive Income										4,693	345,370
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total revenue									1,916,278	1,822,114	1,627,413
Home construction and land sales expenses									1,512,312	1,431,840	1,297,052
Inventory impairments and abandonments									2,389	14,572	3,109
Gross profit									401,577	375,702	327,252
Commissions									74,811	70,460	65,023
General and administrative expenses									161,804	153,524	142,391
Depreciation and amortization									14,009	13,794	13,338
Operating income									150,953	137,924	106,500
Equity in income of unconsolidated entities									371	131	536
Loss on extinguishment of debt									0	0	0
Other expense, net									429	1,061	(258)
Income from continuing operations before income taxes									151,753	139,116	106,778
Expense (benefit) from income taxes									45,266	86,605	(292,326)
Equity in income of subsidiaries									0	0	0
Income from continuing operations									106,487	52,511	399,104
Loss from discontinued operations, net of tax									(115)	(503)	(2,495)
Equity in loss of subsidiaries									0	0	0
Net income									106,372		396,609
Change in unrealized loss related to available-for-sale securities											0
Total Comprehensive Income										52,008	396,609
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total revenue									107	156	198
Home construction and land sales expenses									0	0	0
Inventory impairments and abandonments									0	0	0
Gross profit									107	156	198
Commissions									0	0	0
General and administrative expenses									102	104	105
Depreciation and amortization									0	0	0
Operating income									5	52	93
Equity in income of unconsolidated entities									0	0	0
Loss on extinguishment of debt									0	0	0
Other expense, net									(24)	(3)	(3)
Income from continuing operations before income taxes									(19)	49	90
Expense (benefit) from income taxes									(6)	19	32
Equity in income of subsidiaries									0	0	0
Income from continuing operations									(13)	30	58
Loss from discontinued operations, net of tax									(25)	(9)	(10)
Equity in loss of subsidiaries									0	0	0
Net income									$ (38)		48
Change in unrealized loss related to available-for-sale securities											0
Total Comprehensive Income										$ 21	$ 48