Parent, Issuers, Guarantor and Non-Guarantor Condensed Consolidating Financial Statements - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Assets
Cash and cash equivalents	$ 89,777		$ 77,295	$ 68,056		$ 63,759
Trade and other accounts receivable, net	91,427		90,490
Inventory	953,043		944,338
Other current assets	39,895		42,960
Property and equipment, net	297,124		308,357
Goodwill and other intangible assets, net	601,936		608,623
Other assets	19,412		25,351
Total assets	2,092,614		2,097,414
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	252,470		303,241
Accrued liabilities	156,490		180,287
Income taxes payable	6,280		2,144
Long-term debt	1,713,924		1,774,309
Other liabilities	25,917		30,022
Deferred income tax liabilities, net	82,608		75,967
Total liabilities	2,237,689		2,365,970
Total stockholders’ (deficit) equity	(145,075)	$ (214,731)	(268,556)	(315,029)	$ (342,635)	(363,616)
Total liabilities and stockholders’ (deficit) equity	2,092,614		2,097,414
Parent
Assets
Trade and other accounts receivable, net			4
Other current assets	2,906		2,010
Property and equipment, net	6		8
Investment in subsidiaries	1,489,197		1,368,927
Other assets	1,325		1,325
Total assets	1,493,434		1,372,274
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	85		38
Due to affiliates	1,626,428		1,629,411
Accrued liabilities	359		234
Income taxes payable	5,093		585
Other liabilities	6,729		10,562
Deferred income tax liabilities, net	(185)
Total liabilities	1,638,509		1,640,830
Total stockholders’ (deficit) equity	(145,075)		(268,556)
Total liabilities and stockholders’ (deficit) equity	1,493,434		1,372,274
Sally Holdings and Sally Capital
Assets
Cash and cash equivalents	10		10	10		10
Other current assets	196		111
Investment in subsidiaries	4,206,154		4,044,669
Other assets	3,303		10,242
Total assets	4,209,663		4,055,032
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	3,456
Due to affiliates	982,434		888,141
Accrued liabilities	21,520		23,019
Income taxes payable	1,519		1,519
Long-term debt	1,713,068		1,773,426
Deferred income tax liabilities, net	(1,531)
Total liabilities	2,720,466		2,686,105
Total stockholders’ (deficit) equity	1,489,197		1,368,927
Total liabilities and stockholders’ (deficit) equity	4,209,663		4,055,032
Guarantor Subsidiaries
Assets
Cash and cash equivalents	49,719		29,050	28,211		22,090
Trade and other accounts receivable, net	57,983		53,295
Due from affiliates	2,691,139		2,598,681
Inventory	714,757		714,000
Other current assets	23,399		27,422
Property and equipment, net	230,007		232,941
Investment in subsidiaries	381,353		380,166
Goodwill and other intangible assets, net	456,574		459,348
Other assets	(3,441)		(4,797)
Total assets	4,601,490		4,490,106
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	197,401		233,936
Accrued liabilities	103,095		125,179
Long-term debt	3		1
Other liabilities	15,303		15,250
Deferred income tax liabilities, net	79,534		71,071
Total liabilities	395,336		445,437
Total stockholders’ (deficit) equity	4,206,154		4,044,669
Total liabilities and stockholders’ (deficit) equity	4,601,490		4,490,106
Non-Guarantor Subsidiaries
Assets
Cash and cash equivalents	40,048		48,235	$ 39,835		$ 41,659
Trade and other accounts receivable, net	33,444		37,191
Inventory	238,286		230,338
Other current assets	13,394		13,417
Property and equipment, net	67,111		75,408
Goodwill and other intangible assets, net	145,362		149,275
Other assets	18,225		18,581
Total assets	555,870		572,445
Liabilities and Stockholders’ (Deficit) Equity
Accounts payable	51,528		69,267
Due to affiliates	82,277		81,129
Accrued liabilities	31,516		31,855
Income taxes payable	(332)		40
Long-term debt	853		882
Other liabilities	3,885		4,210
Deferred income tax liabilities, net	4,790		4,896
Total liabilities	174,517		192,279
Total stockholders’ (deficit) equity	381,353		380,166
Total liabilities and stockholders’ (deficit) equity	555,870		572,445
Consolidating Eliminations
Assets
Due from affiliates	(2,691,139)		(2,598,681)
Investment in subsidiaries	(6,076,704)		(5,793,762)
Total assets	(8,767,843)		(8,392,443)
Liabilities and Stockholders’ (Deficit) Equity
Due to affiliates	(2,691,139)		(2,598,681)
Total liabilities	(2,691,139)		(2,598,681)
Total stockholders’ (deficit) equity	(6,076,704)		(5,793,762)
Total liabilities and stockholders’ (deficit) equity	$ (8,767,843)		$ (8,392,443)