Segments and Disaggregated Revenue (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Segments
Number of reportable segments | segment									2
Net sales:
Total net sales	$ 957,812	$ 705,287	$ 871,023	$ 980,208	$ 965,937	$ 975,169	$ 945,852	$ 989,453	$ 3,514,330	$ 3,876,411	$ 3,932,565
Segment operating earnings:
Segment operating earnings									258,760	458,473	426,589
Restructuring									14,025	(682)	33,615
Interest expense									98,793	96,309	98,162
Earnings before provision for income taxes									159,967	362,164	328,427
Depreciation and amortization:
Depreciation and amortization									106,779	107,658	108,829
Payments for property and equipment:
Payments for property and equipment									110,858	107,755	86,507
Total assets:
Assets	2,895,147				2,098,446				$ 2,895,147	$ 2,098,446	$ 2,097,414
Number of single customer accounted for ten percent or more of revenue									10.00%	10.00%	10.00%
Long-lived assets:
Long-lived assets	315,029				319,628				$ 315,029	$ 319,628	$ 308,357
United States
Net sales:
Total net sales									2,914,171	3,169,821	3,188,993
Long-lived assets:
Long-lived assets	264,936				259,815				264,936	259,815	234,475
Foreign
Net sales:
Total net sales									600,159	706,590	743,572
United Kingdom
Long-lived assets:
Long-lived assets	20,183				24,476				20,183	24,476	29,493
Other countries
Long-lived assets:
Long-lived assets	29,910				35,337				29,910	35,337	44,389
Operating segments
Segment operating earnings:
Segment operating earnings									431,794	605,984	603,078
Total assets:
Assets	2,477,546				1,985,640				2,477,546	1,985,640	1,988,668
Corporate
Segment operating earnings:
Unallocated expenses									159,009	148,193	142,874
Depreciation and amortization:
Depreciation and amortization									12,248	13,529	15,079
Payments for property and equipment:
Payments for property and equipment									10,390	18,956	23,620
Total assets:
Assets	417,601				112,806				417,601	112,806	108,746
Sally Beauty Supply
Net sales:
Total net sales									2,080,703	2,293,094	2,333,838
Depreciation and amortization:
Depreciation and amortization									65,207	65,561	64,017
Payments for property and equipment:
Payments for property and equipment									73,130	69,802	46,289
Sally Beauty Supply | Operating segments
Segment operating earnings:
Segment operating earnings									237,588	366,412	362,853
Total assets:
Assets	1,370,745				973,304				1,370,745	973,304	995,546
Beauty Systems Group
Net sales:
Total net sales									1,433,627	1,583,317	1,598,727
Depreciation and amortization:
Depreciation and amortization									29,324	28,568	29,733
Payments for property and equipment:
Payments for property and equipment									27,338	18,997	16,598
Beauty Systems Group | Operating segments
Segment operating earnings:
Segment operating earnings									194,206	239,572	240,225
Total assets:
Assets	$ 1,106,801				$ 1,012,336				$ 1,106,801	$ 1,012,336	$ 993,122