Quarterly Distribution of Available Cash - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Sep. 27, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Quarterly Financial Information Disclosure [Line Items]
Minimum distribution of available cash per unit		$ 0.0675
Common units distribution amount on annualized basis		$ 0.27
First tier, percentage of cash distribution to common units minimum quarterly distribution		100.00%
Second tier, percentage of available cash distribution to common units for any arrearages		100.00%
Third tier, percentage of available cash distribution to general partner unit holder until minimum quarterly distribution is met		100.00%
Fourth tier, percentage of distributions to common unit holders until first target distribution is met		90.00%
Fourth tier, percentage of distributions to general partner unit holder until first target distribution is met		10.00%
First target distribution		$ 0.1125
Thereafter, percentage of distributions to common unit holders after first target distribution is met		80.00%
Thereafter, percentage of distributions to general partner unit holders after first target distribution is met		20.00%
Fixed charge coverage ratio that must be maintained to make distributions	1.15
Annual cash distributions declared per common unit		$ 0.715	$ 0.67	$ 0.63
General partner incentive distributions exclusive of amounts paid subject to management incentive plan		$ 1.5	$ 1.3	$ 1.2
Maximum
Quarterly Financial Information Disclosure [Line Items]
Percentage of excess availability of revolving that must be maintained	15.00%
Availability required to maintained to make distributions	$ 40.0	$ 25.7