Supplemental Guarantor Information - Unaudited Condensed Consolidating Statements of Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities	$ (116,185)	$ (72,062)
Cash flows from investing activities:
Capital expenditures	(8,192)	(5,677)
Proceeds from sale of fixed assets	133	74
Investments in unconsolidated entities	(421)	(2,411)
Return of capital from unconsolidated entities	176	1,621
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(8,304)	(6,393)
Cash flows from financing activities:
Repayment of debt	(401,497)	(256,207)
Proceeds from issuance of new debt	400,000	250,000
Repayment of borrowings from credit facility	(25,000)	(25,000)
Borrowings from credit facility	25,000	25,000
Debt issuance costs	(5,743)	(4,721)
Advances to/from subsidiaries	0	0
Other financing activities	(1,310)	(388)
Net cash used in financing activities	(8,550)	(11,316)
Decrease in cash, cash equivalents, and restricted cash	(133,039)	(89,771)
Cash, cash equivalents, and restricted cash at beginning of period	304,609	243,276
Cash, cash equivalents and restricted cash at end of period	171,570	153,505
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities	0	0
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Investments in unconsolidated entities	0	0
Return of capital from unconsolidated entities	0	0
Advances to/from subsidiaries	186,500	20,009
Net cash used in investing activities	186,500	20,009
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt	0	0
Repayment of borrowings from credit facility	0	0
Borrowings from credit facility	0	0
Debt issuance costs	0	0
Advances to/from subsidiaries	(186,633)	(20,747)
Other financing activities	0	0
Net cash used in financing activities	(186,633)	(20,747)
Decrease in cash, cash equivalents, and restricted cash	(133)	(738)
Cash, cash equivalents, and restricted cash at beginning of period	(7,161)	(4,500)
Cash, cash equivalents and restricted cash at end of period	(7,294)	(5,238)
Beazer Homes USA, Inc.
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities	68,837	(44,754)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Investments in unconsolidated entities	0	0
Return of capital from unconsolidated entities	0	0
Advances to/from subsidiaries	(186,478)	(20,019)
Net cash used in investing activities	(186,478)	(20,019)
Cash flows from financing activities:
Repayment of debt	(400,028)	(253,000)
Proceeds from issuance of new debt	400,000	250,000
Repayment of borrowings from credit facility	(25,000)	(25,000)
Borrowings from credit facility	25,000	25,000
Debt issuance costs	(5,743)	(4,721)
Advances to/from subsidiaries	0	0
Other financing activities	(1,310)	(388)
Net cash used in financing activities	(7,081)	(8,109)
Decrease in cash, cash equivalents, and restricted cash	(124,722)	(72,882)
Cash, cash equivalents, and restricted cash at beginning of period	294,192	228,513
Cash, cash equivalents and restricted cash at end of period	169,470	155,631
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities	(185,014)	(27,243)
Cash flows from investing activities:
Capital expenditures	(8,192)	(5,677)
Proceeds from sale of fixed assets	133	74
Investments in unconsolidated entities	(421)	(2,411)
Return of capital from unconsolidated entities	176	1,621
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(8,304)	(6,393)
Cash flows from financing activities:
Repayment of debt	(1,469)	(3,207)
Proceeds from issuance of new debt	0	0
Repayment of borrowings from credit facility	0	0
Borrowings from credit facility	0	0
Debt issuance costs	0	0
Advances to/from subsidiaries	186,633	20,747
Other financing activities	0	0
Net cash used in financing activities	185,164	17,540
Decrease in cash, cash equivalents, and restricted cash	(8,154)	(16,096)
Cash, cash equivalents, and restricted cash at beginning of period	16,854	18,404
Cash, cash equivalents and restricted cash at end of period	8,700	2,308
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities	(8)	(65)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Investments in unconsolidated entities	0	0
Return of capital from unconsolidated entities	0	0
Advances to/from subsidiaries	(22)	10
Net cash used in investing activities	(22)	10
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt	0	0
Repayment of borrowings from credit facility	0	0
Borrowings from credit facility	0	0
Debt issuance costs	0	0
Advances to/from subsidiaries	0	0
Other financing activities	0	0
Net cash used in financing activities	0	0
Decrease in cash, cash equivalents, and restricted cash	(30)	(55)
Cash, cash equivalents, and restricted cash at beginning of period	724	859
Cash, cash equivalents and restricted cash at end of period	$ 694	$ 804