Supplemental Guarantor Information - Unaudited Condensed Consolidating Statements of Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (83,034)	$ (116,185)
Cash flows from investing activities:
Capital expenditures	(11,508)	(8,192)
Proceeds from sale of fixed assets	94	133
Cash used for business acquisition, net of cash acquired	(4,088)	0
Investments in unconsolidated entities	0	(421)
Return of capital from unconsolidated entities	0	176
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(15,502)	(8,304)
Cash flows from financing activities:
Repayment of debt	(5,062)	(401,497)
Proceeds from issuance of new debt	0	400,000
Borrowings from credit facility	225,000	25,000
Repayment of borrowings from credit facility	(150,000)	(25,000)
Debt issuance costs	(400)	(5,743)
Repurchase of common stock	(24,004)	0
Tax payments for stock-based compensation awards	(1,886)	(1,323)
Stock option exercises	278	13
Advances to/from subsidiaries	0	0
Net cash provided by (used in) financing activities	43,926	(8,550)
Decrease in cash, cash equivalents, and restricted cash	(54,610)	(133,039)
Cash, cash equivalents, and restricted cash at beginning of period	153,248	304,609
Cash, cash equivalents, and restricted cash at end of period	98,638	171,570
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Cash used for business acquisition, net of cash acquired	0
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities		0
Advances to/from subsidiaries	(43,528)	186,500
Net cash used in investing activities	(43,528)	186,500
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt		0
Borrowings from credit facility	0	0
Repayment of borrowings from credit facility	0	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Stock option exercises	0	0
Advances to/from subsidiaries	43,528	(186,633)
Net cash provided by (used in) financing activities	43,528	(186,633)
Decrease in cash, cash equivalents, and restricted cash	0	(133)
Cash, cash equivalents, and restricted cash at beginning of period	0	(7,161)
Cash, cash equivalents, and restricted cash at end of period	0	(7,294)
Beazer Homes USA, Inc. | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(101,323)	68,837
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Cash used for business acquisition, net of cash acquired	0
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities		0
Advances to/from subsidiaries	44,061	(186,478)
Net cash used in investing activities	44,061	(186,478)
Cash flows from financing activities:
Repayment of debt	(5,062)	(400,028)
Proceeds from issuance of new debt		400,000
Borrowings from credit facility	225,000	25,000
Repayment of borrowings from credit facility	(150,000)	(25,000)
Debt issuance costs	(400)	(5,743)
Repurchase of common stock	(24,004)
Tax payments for stock-based compensation awards	(1,886)	(1,323)
Stock option exercises	278	13
Advances to/from subsidiaries	0	0
Net cash provided by (used in) financing activities	43,926	(7,081)
Decrease in cash, cash equivalents, and restricted cash	(13,336)	(124,722)
Cash, cash equivalents, and restricted cash at beginning of period	104,796	294,192
Cash, cash equivalents, and restricted cash at end of period	91,460	169,470
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	18,324	(185,014)
Cash flows from investing activities:
Capital expenditures	(11,508)	(8,192)
Proceeds from sale of fixed assets	94	133
Cash used for business acquisition, net of cash acquired	(4,088)
Investments in unconsolidated entities		(421)
Return of capital from unconsolidated entities		176
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(15,502)	(8,304)
Cash flows from financing activities:
Repayment of debt	0	(1,469)
Proceeds from issuance of new debt		0
Borrowings from credit facility	0	0
Repayment of borrowings from credit facility	0	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Stock option exercises	0	0
Advances to/from subsidiaries	(43,528)	186,633
Net cash provided by (used in) financing activities	(43,528)	185,164
Decrease in cash, cash equivalents, and restricted cash	(40,706)	(8,154)
Cash, cash equivalents, and restricted cash at beginning of period	47,877	16,854
Cash, cash equivalents, and restricted cash at end of period	7,171	8,700
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(35)	(8)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Cash used for business acquisition, net of cash acquired	0
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities		0
Advances to/from subsidiaries	(533)	(22)
Net cash used in investing activities	(533)	(22)
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt		0
Borrowings from credit facility	0	0
Repayment of borrowings from credit facility	0	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Stock option exercises	0	0
Advances to/from subsidiaries	0	0
Net cash provided by (used in) financing activities	0	0
Decrease in cash, cash equivalents, and restricted cash	(568)	(30)
Cash, cash equivalents, and restricted cash at beginning of period	575	724
Cash, cash equivalents, and restricted cash at end of period	$ 7	$ 694