Related Parties - Narrative (Detail) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Operating lease right-of-use assets	[1]	$ 73,444				$ 73,444		$ 66,962
Non-current operating lease liabilities	[2]	61,544				61,544		55,329
Selling, general and administrative	[3]	165,937	[4],[5]	$ 183,883	[4],[5]	314,021	$ 297,986
Related party interest income		$ 0		15		$ 3	29
Weber Inc.
Tax receivable agreement, certain cash tax benefits, percent		85.00%				85.00%
Tax receivable agreement liability		$ 9,200				$ 9,200		9,200
Weber Inc. | Secured Credit Facility Incremental Term Loan, due October 2027
Related party rental expense		600
Royalty
Revenue from related parties		129		(97)		273	(54)
Royalty receivables		100				100		100
Rental Expense
Operating lease expense		0		300		0	500
Related party rental expense		0		213		0	392
Rental Expense | AUSTRALIA
Operating lease expense		100		0		300	0
Operating lease right-of-use assets		1,500				1,500		1,600
Operating lease liability, current		400				400		400
Non-current operating lease liabilities		1,100				1,100		1,200
June
Related party, royalty expense		0		0		0	300
Member Notes
Total amount due from members on the notes receivable		0				0		$ 11,300
Related party interest income		0		$ 0		0	0
Discount Granted As Concession | Royalty
Revenue from related parties							$ 100
Reassignment of Insurance Policy Beneficiary to Related Party
Selling, general and administrative		$ 400				$ 400

[1] Includes related party operating lease assets of $1,492 and $1,629 at March 31, 2022 and September 30, 2021, respectively (see Note 9).

[2] Includes related party operating lease liabilities of $1,043 and $1,198 at March 31, 2022 and September 30, 2021, respectively (see Note 9).

[3] Includes related party compensation expense of $420 and zero for the three months ended March 31, 2022 and 2021, respectively, and $420 and zero for the six months ended March 31, 2022 and 2021, respectively (see Note 9).

[4] Includes related party rental expense of $170 and $69 for the three months ended March 31, 2022 and 2021, respectively, and $337 and $128 for the six months ended March 31, 2022 and 2021, respectively (see Note 9).

[5] Includes related party royalty expense of zero and zero for the three months ended March 31, 2022 and 2021, respectively, and zero and $268 for the six months ended March 31, 2022 and 2021, respectively (see Note 9).