Segments and Disaggregated Revenue (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Segments
Number of reportable segments | segment									2
Net sales:
Total net sales	$ 965,937	$ 975,169	$ 945,852	$ 989,453	$ 965,997	$ 996,283	$ 975,321	$ 994,964	$ 3,876,411	$ 3,932,565	$ 3,938,317
Segment operating earnings:
Segment operating earnings									458,473	426,589	478,597
Restructuring									682	(33,615)	(22,679)
Interest expense									(96,309)	(98,162)	(132,899)
Earnings before provision for income taxes									362,164	328,427	345,698
Depreciation and amortization:
Depreciation and amortization									107,658	108,829	112,323
Payments for property and equipment:
Payments for property and equipment									107,755	86,507	89,666
Total assets:
Assets	2,098,446				2,097,414				$ 2,098,446	$ 2,097,414	$ 2,099,007
Number of single customer accounted for ten percent or more of revenue									10.00%	10.00%	10.00%
Long-lived assets:
Long-lived assets	319,628				308,357				$ 319,628	$ 308,357	$ 313,717
United States
Net sales:
Total net sales									3,169,821	3,188,993	3,248,662
Long-lived assets:
Long-lived assets	259,815				234,475				259,815	234,475	230,698
Foreign
Net sales:
Total net sales									706,590	743,572	689,655
United Kingdom
Long-lived assets:
Long-lived assets	24,476				29,493				24,476	29,493	32,771
Other countries
Long-lived assets:
Long-lived assets	35,337				44,389				35,337	44,389	50,248
Operating segments
Segment operating earnings:
Segment operating earnings									605,984	603,078	640,098
Total assets:
Assets	1,985,640				1,988,668				1,985,640	1,988,668	1,990,529
Corporate
Segment operating earnings:
Unallocated expenses									(148,193)	(142,874)	(138,822)
Depreciation and amortization:
Depreciation and amortization									13,529	15,079	17,141
Payments for property and equipment:
Payments for property and equipment									18,956	23,620	18,153
Total assets:
Assets	112,806				108,746				112,806	108,746	108,478
Sally Beauty Supply
Net sales:
Total net sales									2,293,094	2,333,838	2,345,116
Depreciation and amortization:
Depreciation and amortization									65,561	64,017	63,427
Payments for property and equipment:
Payments for property and equipment									69,802	46,289	52,178
Sally Beauty Supply | Operating segments
Segment operating earnings:
Segment operating earnings									366,412	362,853	385,407
Total assets:
Assets	973,304				995,546				973,304	995,546	1,025,545
Beauty Systems Group
Net sales:
Total net sales									1,583,317	1,598,727	1,593,201
Depreciation and amortization:
Depreciation and amortization									28,568	29,733	31,755
Payments for property and equipment:
Payments for property and equipment									18,997	16,598	19,335
Beauty Systems Group | Operating segments
Segment operating earnings:
Segment operating earnings									239,572	240,225	254,691
Total assets:
Assets	$ 1,012,336				$ 993,122				$ 1,012,336	$ 993,122	$ 964,984