Separate Financial Information of Guarantor Subsidiaries - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Assets
Cash and cash equivalents	$ 71,495	$ 77,295	$ 63,759	$ 86,622
Trade and other accounts receivable, net	104,539	90,490
Inventory	952,907	944,338
Other current assets	34,612	42,960
Property and equipment, net	319,628	308,357	313,717
Goodwill and other intangible assets, net	592,837	608,623
Other assets	22,428	25,351
Total assets	2,098,446	2,097,414	2,099,007
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	278,688	303,241
Accrued liabilities	169,054	180,287
Income taxes payable	8,336	2,144
Long-term debt	1,594,543	1,774,309
Other liabilities	27,757	30,022
Deferred income tax liabilities, net	80,391	75,967
Total liabilities	2,158,769	2,365,970
Total stockholders’ (deficit) equity	(60,323)	(268,556)	(363,616)	(276,166)
Total liabilities and stockholders’ deficit	2,098,446	2,097,414
Parent
Assets
Trade and other accounts receivable, net		4
Other current assets	1,436	2,010
Property and equipment, net	6	8
Investment in subsidiaries	1,621,843	1,368,927
Other assets	1,446	1,325
Total assets	1,624,731	1,372,274
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	48	38
Due to affiliates	1,672,322	1,629,411
Accrued liabilities	188	234
Income taxes payable	6,055	585
Other liabilities	6,441	10,562
Total liabilities	1,685,054	1,640,830
Total stockholders’ (deficit) equity	(60,323)	(268,556)
Total liabilities and stockholders’ deficit	1,624,731	1,372,274
Sally Holdings and Sally Capital
Assets
Cash and cash equivalents	10	10	10	28,372
Other current assets	132	111
Investment in subsidiaries	4,374,334	4,044,669
Other assets	3,499	10,242
Total assets	4,377,975	4,055,032
Liabilities and Stockholders’ (Deficit) Equity
Due to affiliates	1,142,324	888,141
Accrued liabilities	17,937	23,019
Income taxes payable	2,161	1,519
Long-term debt	1,593,710	1,773,426
Total liabilities	2,756,132	2,686,105
Total stockholders’ (deficit) equity	1,621,843	1,368,927
Total liabilities and stockholders’ deficit	4,377,975	4,055,032
Guarantor Subsidiaries
Assets
Cash and cash equivalents	41,009	29,050	22,090	22,368
Trade and other accounts receivable, net	65,746	53,295
Due from affiliates	2,878,072	2,598,681
Inventory	722,830	714,000
Other current assets	22,480	27,422
Property and equipment, net	258,132	232,941
Investment in subsidiaries	385,629	380,166
Goodwill and other intangible assets, net	452,645	459,348
Other assets	(581)	(4,797)
Total assets	4,825,962	4,490,106
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	235,940	233,936
Accrued liabilities	121,375	125,179
Income taxes payable	1
Long-term debt	1	1
Other liabilities	17,639	15,250
Deferred income tax liabilities, net	76,672	71,071
Total liabilities	451,628	445,437
Total stockholders’ (deficit) equity	4,374,334	4,044,669
Total liabilities and stockholders’ deficit	4,825,962	4,490,106
Non-Guarantor Subsidiaries
Assets
Cash and cash equivalents	30,476	48,235	$ 41,659	$ 35,882
Trade and other accounts receivable, net	38,793	37,191
Inventory	230,077	230,338
Other current assets	10,564	13,417
Property and equipment, net	61,490	75,408
Goodwill and other intangible assets, net	140,192	149,275
Other assets	18,064	18,581
Total assets	529,656	572,445
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	42,700	69,267
Due to affiliates	63,426	81,129
Accrued liabilities	29,554	31,855
Income taxes payable	119	40
Long-term debt	832	882
Other liabilities	3,677	4,210
Deferred income tax liabilities, net	3,719	4,896
Total liabilities	144,027	192,279
Total stockholders’ (deficit) equity	385,629	380,166
Total liabilities and stockholders’ deficit	529,656	572,445
Consolidating Eliminations
Assets
Due from affiliates	(2,878,072)	(2,598,681)
Investment in subsidiaries	(6,381,806)	(5,793,762)
Total assets	(9,259,878)	(8,392,443)
Liabilities and Stockholders’ (Deficit) Equity
Due to affiliates	(2,878,072)	(2,598,681)
Total liabilities	(2,878,072)	(2,598,681)
Total stockholders’ (deficit) equity	(6,381,806)	(5,793,762)
Total liabilities and stockholders’ deficit	$ (9,259,878)	$ (8,392,443)