Supplemental Guarantor Information - Unaudited Condensed Consolidating Statements of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (54,690)	$ (102,224)
Cash flows from investing activities:
Capital expenditures	(6,354)	(3,702)
Proceeds from sale of fixed assets	54	84
Investments in unconsolidated entities	0	(421)
Return of capital from unconsolidated entities	0
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(6,300)	(4,039)
Cash flows from financing activities:
Repayment of debt	(1,479)	(401,481)
Proceeds from issuance of new debt	0	400,000
Repayment of borrowings from credit facility	(75,000)	0
Borrowings from credit facility	100,000	0
Debt issuance costs	(400)	(5,649)
Repurchase of common stock	(16,500)	0
Tax payments for stock-based compensation awards	(1,850)	(1,322)
Advances to/from subsidiaries	0	0
Other financing activities	7	0
Net cash provided by (used in) financing activities	4,778	(8,452)
Decrease in cash, cash equivalents, and restricted cash	(56,212)	(114,715)
Cash, cash equivalents, and restricted cash at beginning of period	153,248	304,609
Cash, cash equivalents, and restricted cash at end of period	97,036	189,894
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
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities	0
Advances to/from subsidiaries	(21,204)	187,477
Net cash used in investing activities	(21,204)	187,477
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt		0
Repayment of borrowings from credit facility	0
Borrowings from credit facility	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Advances to/from subsidiaries	21,204	(186,563)
Other financing activities	0	0
Net cash provided by (used in) financing activities	21,204	(186,563)
Decrease in cash, cash equivalents, and restricted cash	0	914
Cash, cash equivalents, and restricted cash at beginning of period	0	(7,161)
Cash, cash equivalents, and restricted cash at end of period	0	(6,247)
Beazer Homes USA, Inc.
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(31,908)	91,465
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities	532
Advances to/from subsidiaries	21,204	(187,451)
Net cash used in investing activities	21,736	(187,451)
Cash flows from financing activities:
Repayment of debt	(11)	(400,012)
Proceeds from issuance of new debt		400,000
Repayment of borrowings from credit facility	(75,000)
Borrowings from credit facility	100,000
Debt issuance costs	(400)	(5,649)
Repurchase of common stock	(16,500)
Tax payments for stock-based compensation awards	(1,850)	(1,322)
Advances to/from subsidiaries	0	0
Other financing activities	7	0
Net cash provided by (used in) financing activities	6,246	(6,983)
Decrease in cash, cash equivalents, and restricted cash	(3,926)	(102,969)
Cash, cash equivalents, and restricted cash at beginning of period	104,796	294,192
Cash, cash equivalents, and restricted cash at end of period	100,870	191,223
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(22,756)	(193,721)
Cash flows from investing activities:
Capital expenditures	(6,354)	(3,702)
Proceeds from sale of fixed assets	54	84
Investments in unconsolidated entities		(421)
Return of capital from unconsolidated entities	0
Advances to/from subsidiaries	0	0
Net cash used in investing activities	(6,300)	(4,039)
Cash flows from financing activities:
Repayment of debt	(1,468)	(1,469)
Proceeds from issuance of new debt		0
Repayment of borrowings from credit facility	0
Borrowings from credit facility	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Advances to/from subsidiaries	(21,204)	186,563
Other financing activities	0	0
Net cash provided by (used in) financing activities	(22,672)	185,094
Decrease in cash, cash equivalents, and restricted cash	(51,728)	(12,666)
Cash, cash equivalents, and restricted cash at beginning of period	47,877	16,854
Cash, cash equivalents, and restricted cash at end of period	(3,851)	4,188
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(26)	32
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from sale of fixed assets	0	0
Investments in unconsolidated entities		0
Return of capital from unconsolidated entities	(532)
Advances to/from subsidiaries	0	(26)
Net cash used in investing activities	(532)	(26)
Cash flows from financing activities:
Repayment of debt	0	0
Proceeds from issuance of new debt		0
Repayment of borrowings from credit facility	0
Borrowings from credit facility	0
Debt issuance costs	0	0
Repurchase of common stock	0
Tax payments for stock-based compensation awards	0	0
Advances to/from subsidiaries	0	0
Other financing activities	0	0
Net cash provided by (used in) financing activities	0	0
Decrease in cash, cash equivalents, and restricted cash	(558)	6
Cash, cash equivalents, and restricted cash at beginning of period	575	724
Cash, cash equivalents, and restricted cash at end of period	$ 17	$ 730