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, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2020	Mar. 31, 2019
Condensed Income Statements Captions [Line Items]
Net sales	$ 871,023		$ 945,852		$ 1,851,231	$ 1,935,305
Cost of goods sold	441,266		477,528		946,626	986,275
Gross profit	429,757		468,324		904,605	949,030
Selling, general and administrative expenses	383,299		361,626		761,228	728,614
Restructuring	3,193		(5,814)		5,725	(1,834)
Operating earnings	43,265		112,512		137,652	222,250
Interest expense (income)	21,644		23,821
Earnings before provision for income taxes	21,621		88,691		94,467	173,940
Provision (benefit) for income taxes	8,253		22,966		27,884	42,488
Net earnings	13,368	$ 53,215	65,725	$ 65,727	66,583	131,452
Other comprehensive income (loss), net of tax	(21,826)	$ 14,870	1,142	$ (16,705)	(6,956)	(15,563)
Total comprehensive income (loss)	(8,458)		66,867		$ 59,627	$ 115,889
Parent
Condensed Income Statements Captions [Line Items]
Selling, general and administrative expenses	2,758		3,084
Operating earnings	(2,758)		(3,084)
Earnings before provision for income taxes	(2,758)		(3,084)
Provision (benefit) for income taxes	(708)		(791)
Equity in earnings (loss) of subsidiaries, net of tax	15,418		68,018
Net earnings	13,368		65,725
Total comprehensive income (loss)	13,368		65,725
Sally Holdings and Sally Capital
Condensed Income Statements Captions [Line Items]
Selling, general and administrative expenses	179		198
Operating earnings	(179)		(198)
Interest expense (income)	21,652		23,871
Earnings before provision for income taxes	(21,831)		(24,069)
Provision (benefit) for income taxes	(5,604)		(6,179)
Equity in earnings (loss) of subsidiaries, net of tax	31,645		85,908
Net earnings	15,418		68,018
Other comprehensive income (loss), net of tax	(80)		(2,140)
Total comprehensive income (loss)	15,338		65,878
Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Net sales	713,872		769,284
Related party sales	382		480
Cost of goods sold	355,373		383,147
Gross profit	358,881		386,617
Selling, general and administrative expenses	306,197		281,404
Restructuring	3,193		(5,814)
Operating earnings	49,491		111,027
Interest expense (income)	3		(1)
Earnings before provision for income taxes	49,488		111,028
Provision (benefit) for income taxes	11,502		28,795
Equity in earnings (loss) of subsidiaries, net of tax	(6,341)		3,675
Net earnings	31,645		85,908
Total comprehensive income (loss)	31,645		85,908
Non-Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Net sales	157,151		176,568
Cost of goods sold	86,275		94,861
Gross profit	70,876		81,707
Selling, general and administrative expenses	74,165		76,940
Operating earnings	(3,289)		4,767
Interest expense (income)	(11)		(49)
Earnings before provision for income taxes	(3,278)		4,816
Provision (benefit) for income taxes	3,063		1,141
Net earnings	(6,341)		3,675
Other comprehensive income (loss), net of tax	(21,746)		3,282
Total comprehensive income (loss)	(28,087)		6,957
Consolidating Eliminations
Condensed Income Statements Captions [Line Items]
Related party sales	(382)		(480)
Cost of goods sold	(382)		(480)
Equity in earnings (loss) of subsidiaries, net of tax	(40,722)		(157,601)
Net earnings	(40,722)		(157,601)
Total comprehensive income (loss)	$ (40,722)		$ (157,601)