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 (loss) income	101,946	$ 101,946
Other comprehensive income	1,623		1,623
Partnership distributions	(111,562)	(111,562)
Common Units issued under Restricted Unit Plans	(1,761)	$ (1,761)
Common Units issued under Restricted Unit Plans (in units)		398
Recognition in earnings of net actuarial loss for pension settlement	900		900
Compensation costs recognized under Restricted Unit Plans	7,084	$ 7,084
Balance, end of period at Jun. 27, 2020	422,168	$ 445,831	(23,663)
Balance (in units) at Jun. 27, 2020		62,133
Balance, beginning of period at Mar. 28, 2020	471,322	$ 496,426	(25,104)
Balance (in units) at Mar. 28, 2020		62,073
Net (loss) income	(15,578)	$ (15,578)	0
Other comprehensive income	541		541
Partnership distributions	(37,279)	(37,279)
Common Units issued under Restricted Unit Plans	0	$ 0
Common Units issued under Restricted Unit Plans (in units)		60
Recognition in earnings of net actuarial loss for pension settlement	900	$ 0	900
Compensation costs recognized under Restricted Unit Plans	2,262	2,262
Balance, end of period at Jun. 27, 2020	422,168	$ 445,831	(23,663)
Balance (in units) at Jun. 27, 2020		62,133
Balance, beginning of period at Sep. 26, 2020	362,381	$ 388,157	(25,776)
Balance (in units) at Sep. 26, 2020		62,146
Net (loss) income	139,172	$ 139,172
Other comprehensive income	1,779		1,779
Partnership distributions	(56,159)	(56,159)
Common Units issued under Restricted Unit Plans	(1,534)	$ (1,534)
Common Units issued under Restricted Unit Plans (in units)		383
Recognition in earnings of net actuarial loss for pension settlement	712		712
Compensation costs recognized under Restricted Unit Plans	7,524	$ 7,524
Balance, end of period at Jun. 26, 2021	453,875	$ 477,160	(23,285)
Balance (in units) at Jun. 26, 2021		62,529
Balance, beginning of period at Mar. 27, 2021	495,348	$ 519,368	(24,020)
Balance (in units) at Mar. 27, 2021		62,529
Net (loss) income	(26,021)	$ (26,021)
Other comprehensive income	593		593
Partnership distributions	(18,758)	$ (18,758)
Common Units issued under Restricted Unit Plans (in units)		0
Recognition in earnings of net actuarial loss for pension settlement	142		142
Compensation costs recognized under Restricted Unit Plans	2,571	$ 2,571
Balance, end of period at Jun. 26, 2021	$ 453,875	$ 477,160	$ (23,285)
Balance (in units) at Jun. 26, 2021		62,529