Employee Benefit Plans - Schedule of Measurement of Partnership's Pension Plan Assets by Category (Details) - Pension Benefits [Member] - USD ($) $ in Thousands		Sep. 25, 2021	Sep. 26, 2020	Sep. 28, 2019
Deferred Compensation Arrangement With Individual Postretirement Benefits [Line Items]
Fair value of plan assets		$ 77,892	$ 80,001	$ 80,913
Short-term investments [Member]
Deferred Compensation Arrangement With Individual Postretirement Benefits [Line Items]
Fair value of plan assets	[1]	1,467	1,485
Domestic equity securities [Member]
Deferred Compensation Arrangement With Individual Postretirement Benefits [Line Items]
Fair value of plan assets	[1],[2]	4,129	4,138
International equity securities [Member]
Deferred Compensation Arrangement With Individual Postretirement Benefits [Line Items]
Fair value of plan assets	[1],[2]	7,167	7,117
Fixed income securities [Member]
Deferred Compensation Arrangement With Individual Postretirement Benefits [Line Items]
Fair value of plan assets	[1],[3]	$ 65,129	$ 67,261

[1] Includes funds which are not publicly traded and are valued at the net asset value of the units provided by the fund issuer.

[2] Includes funds which invest primarily in a diversified portfolio of publicly traded U.S. and Non-U.S. common stock.

[3] Includes funds which invest primarily in publicly traded and non-publicly traded, investment grade corporate bonds, U.S. government bonds and asset-backed securities.