Parent, Issuers, Guarantor and Non-Guarantor Condensed Consolidating Financial Statements - Condensed Consolidating Statement of Earnings and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Mar. 31, 2018
Condensed Income Statements Captions [Line Items]
Net sales	$ 945,852		$ 975,321		$ 1,935,305	$ 1,970,286
Cost of products sold and distribution expenses	477,528		488,999		986,275	997,335
Gross profit	468,324		486,322		949,030	972,951
Selling, general and administrative expenses	361,626		368,461		728,614	739,748
Restructuring	(5,814)		6,759		(1,834)	11,969
Operating earnings	112,512		111,102		222,250	221,234
Interest expense (income)	23,821		25,262		48,310	49,277
Earnings before provision for income taxes	88,691		85,840		173,940	171,957
Provision (benefit) for income taxes	22,966		24,469		42,488	27,322
Net earnings	65,725	$ 65,727	61,371	$ 83,264	131,452	144,635
Other comprehensive income (loss), net of tax	1,142	$ (16,705)	12,747	$ (1,058)	(15,563)	11,689
Total comprehensive income	66,867		74,118		115,889	156,324
Parent
Condensed Income Statements Captions [Line Items]
Selling, general and administrative expenses	3,084		2,859		5,893	5,465
Operating earnings	(3,084)		(2,859)		(5,893)	(5,465)
Earnings before provision for income taxes	(3,084)		(2,859)		(5,893)	(5,465)
Provision (benefit) for income taxes	(791)		(828)		(1,512)	(1,079)
Equity in earnings of subsidiaries, net of tax	68,018		63,402		135,833	149,021
Net earnings	65,725		61,371		131,452	144,635
Total comprehensive income	65,725		61,371		131,452	144,635
Sally Holdings and Sally Capital
Condensed Income Statements Captions [Line Items]
Selling, general and administrative expenses	198		602		366	781
Operating earnings	(198)		(602)		(366)	(781)
Interest expense (income)	23,871		25,293		48,423	49,307
Earnings before provision for income taxes	(24,069)		(25,895)		(48,789)	(50,088)
Provision (benefit) for income taxes	(6,179)		(7,499)		(12,524)	(14,424)
Equity in earnings of subsidiaries, net of tax	85,908		81,798		172,098	184,685
Net earnings	68,018		63,402		135,833	149,021
Other comprehensive income (loss), net of tax	(2,140)		2,310		(4,949)	1,507
Total comprehensive income	65,878		65,712		130,884	150,528
Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Net sales	769,284		786,743		1,562,814	1,583,275
Related party sales	480		631		1,149	1,077
Cost of products sold and distribution expenses	383,147		390,891		787,187	794,701
Gross profit	386,617		396,483		776,776	789,651
Selling, general and administrative expenses	281,404		279,435		567,620	563,902
Restructuring	(5,814)		6,759		(1,834)	11,969
Operating earnings	111,027		110,289		210,990	213,780
Interest expense (income)	(1)		(3)		(2)	(3)
Earnings before provision for income taxes	111,028		110,292		210,992	213,783
Provision (benefit) for income taxes	28,795		30,758		54,478	22,843
Equity in earnings of subsidiaries, net of tax	3,675		2,264		15,584	(6,255)
Net earnings	85,908		81,798		172,098	184,685
Total comprehensive income	85,908		81,798		172,098	184,685
Non-Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Net sales	176,568		188,578		372,491	387,011
Cost of products sold and distribution expenses	94,861		98,739		200,237	203,711
Gross profit	81,707		89,839		172,254	183,300
Selling, general and administrative expenses	76,940		85,565		154,735	169,600
Operating earnings	4,767		4,274		17,519	13,700
Interest expense (income)	(49)		(28)		(111)	(27)
Earnings before provision for income taxes	4,816		4,302		17,630	13,727
Provision (benefit) for income taxes	1,141		2,038		2,046	19,982
Net earnings	3,675		2,264		15,584	(6,255)
Other comprehensive income (loss), net of tax	3,282		10,437		(10,614)	10,182
Total comprehensive income	6,957		12,701		4,970	3,927
Consolidating Eliminations
Condensed Income Statements Captions [Line Items]
Related party sales	(480)		(631)		(1,149)	(1,077)
Cost of products sold and distribution expenses	(480)		(631)		(1,149)	(1,077)
Equity in earnings of subsidiaries, net of tax	(157,601)		(147,464)		(323,515)	(327,451)
Net earnings	(157,601)		(147,464)		(323,515)	(327,451)
Total comprehensive income	$ (157,601)		$ (147,464)		$ (323,515)	$ (327,451)