Separate Financial Information of Guarantor Subsidiaries - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Condensed Cash Flow Statements Captions [Line Items]
Net cash provided (used) by operating activities	$ 320,415	$ 372,661	$ 343,286
Cash Flows from Investing Activities:
Payments for property and equipment, net	(92,443)	(86,138)	(89,625)
Acquisitions, net of cash acquired	(3,424)	(9,175)
Net cash used by investing activities	(95,867)	(95,313)	(89,625)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt	593,504	461,819	1,277,250
Repayments of long-term debt	(777,538)	(558,599)	(1,216,643)
Debt issuance costs		(1,151)	(8,376)
Payments for common stock repurchased	(47,434)	(166,701)	(346,873)
Proceeds from exercises of stock options	2,160	1,350	17,339
Net cash used by financing activities	(229,308)	(263,282)	(277,303)
Effect of foreign exchange rate changes on cash and cash equivalents	(1,040)	(530)	779
Net increase (decrease) in cash and cash equivalents	(5,800)	13,536	(22,863)
Cash and cash equivalents, beginning of period	77,295	63,759	86,622
Cash and cash equivalents, end of period	71,495	77,295	63,759
Parent
Condensed Cash Flow Statements Captions [Line Items]
Net cash provided (used) by operating activities	2,364	23,424	4,095
Cash Flows from Investing Activities:
Payments for property and equipment, net	(1)
Net cash used by investing activities	(1)
Cash Flows from Financing Activities:
Payments for common stock repurchased	(47,434)	(166,701)	(346,873)
Proceeds from exercises of stock options	2,160	1,350	17,339
Due to affiliates	42,911	141,927	325,439
Net cash used by financing activities	(2,363)	(23,424)	(4,095)
Sally Holdings and Sally Capital
Condensed Cash Flow Statements Captions [Line Items]
Net cash provided (used) by operating activities	(70,150)	(62,948)	(72,779)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt	593,500	461,814	1,277,250
Repayments of long-term debt	(777,533)	(558,000)	(1,215,940)
Debt issuance costs		(1,151)	(8,376)
Due to affiliates	254,183	160,285	(8,517)
Net cash used by financing activities	70,150	62,948	44,417
Net increase (decrease) in cash and cash equivalents			(28,362)
Cash and cash equivalents, beginning of period	10	10	28,372
Cash and cash equivalents, end of period	10	10	10
Guarantor Subsidiaries
Condensed Cash Flow Statements Captions [Line Items]
Net cash provided (used) by operating activities	373,313	384,958	386,604
Cash Flows from Investing Activities:
Payments for property and equipment, net	(79,379)	(68,689)	(64,000)
Acquisitions, net of cash acquired	(2,584)
Due from affiliates	(279,391)	(309,310)	(322,866)
Net cash used by investing activities	(361,354)	(377,999)	(386,866)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt	4	5
Repayments of long-term debt	(4)	(4)	(16)
Net cash used by financing activities		1	(16)
Net increase (decrease) in cash and cash equivalents	11,959	6,960	(278)
Cash and cash equivalents, beginning of period	29,050	22,090	22,368
Cash and cash equivalents, end of period	41,009	29,050	22,090
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements Captions [Line Items]
Net cash provided (used) by operating activities	14,888	27,227	25,366
Cash Flows from Investing Activities:
Payments for property and equipment, net	(13,063)	(17,449)	(25,625)
Acquisitions, net of cash acquired	(840)	(9,175)
Net cash used by investing activities	(13,903)	(26,624)	(25,625)
Cash Flows from Financing Activities:
Repayments of long-term debt	(1)	(595)	(687)
Due to affiliates	(17,703)	7,098	5,944
Net cash used by financing activities	(17,704)	6,503	5,257
Effect of foreign exchange rate changes on cash and cash equivalents	(1,040)	(530)	779
Net increase (decrease) in cash and cash equivalents	(17,759)	6,576	5,777
Cash and cash equivalents, beginning of period	48,235	41,659	35,882
Cash and cash equivalents, end of period	30,476	48,235	41,659
Consolidating Eliminations
Cash Flows from Investing Activities:
Due from affiliates	279,391	309,310	322,866
Net cash used by investing activities	279,391	309,310	322,866
Cash Flows from Financing Activities:
Due to affiliates	(279,391)	(309,310)	(322,866)
Net cash used by financing activities	$ (279,391)	$ (309,310)	$ (322,866)