CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Unitholders [Member]	Accumulated Other Comprehensive (Loss) [Member]
Balance, beginning of period at Sep. 28, 2019	$ 423,938	$ 450,124	$ (26,186)
Balance (in units) at Sep. 28, 2019		61,735
Net income	40,163	$ 40,163
Other comprehensive income	541		541
Partnership distributions	(37,041)	(37,041)
Common Units issued under Restricted Unit Plans	(1,729)	$ (1,729)
Common Units issued under Restricted Unit Plans (in units)		335
Compensation costs recognized under Restricted Unit Plans	2,562	$ 2,562
Balance, end of period at Dec. 28, 2019	428,434	$ 454,079	(25,645)
Balance (in units) at Dec. 28, 2019		62,070
Balance, beginning of period at Sep. 26, 2020	362,381	$ 388,157	(25,776)
Balance (in units) at Sep. 26, 2020		62,146
Net income	37,977	$ 37,977
Other comprehensive income	593		593
Partnership distributions	(18,644)	(18,644)
Common Units issued under Restricted Unit Plans	(1,503)	$ (1,503)
Common Units issued under Restricted Unit Plans (in units)		376
Compensation costs recognized under Restricted Unit Plans	2,358	$ 2,358
Balance, end of period at Dec. 26, 2020	$ 383,162	$ 408,345	$ (25,183)
Balance (in units) at Dec. 26, 2020		62,522