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. 29, 2018	$ 493,824	$ 518,494	$ (24,670)
Balance (in units) at Sep. 29, 2018		61,405
Net income	148,735	$ 148,735
Other comprehensive income	1,104		1,104
Partnership distributions	(73,841)	(73,841)
Common Units issued under Restricted Unit Plans	(1,349)	$ (1,349)
Common Units issued under Restricted Unit Plans (in units)		259
Compensation costs recognized under Restricted Unit Plans	6,575	$ 6,575
Balance, end of period at Mar. 30, 2019	575,048	$ 598,614	(23,566)
Balance (in units) at Mar. 30, 2019		61,664
Balance, beginning of period at Dec. 29, 2018	486,924	$ 511,042	(24,118)
Balance (in units) at Dec. 29, 2018		61,664
Net income	121,016	$ 121,016
Other comprehensive income	552		552
Partnership distributions	(36,998)	(36,998)
Common Units issued under Restricted Unit Plans	0	$ 0
Common Units issued under Restricted Unit Plans (in units)		0
Compensation costs recognized under Restricted Unit Plans	3,554	$ 3,554
Balance, end of period at Mar. 30, 2019	575,048	$ 598,614	(23,566)
Balance (in units) at Mar. 30, 2019		61,664
Balance, beginning of period at Sep. 28, 2019	423,830
Balance, beginning of period (Including Cumulative Effect Adjustment of Lease Operation on Retained Earnings [Member]) at Sep. 28, 2019	423,938	$ 450,124	(26,186)
Balance (in units) (Including Cumulative Effect Adjustment of Lease Operation on Retained Earnings [Member]) at Sep. 28, 2019		61,735
Net income	117,524	$ 117,524
Other comprehensive income	1,082		1,082
Partnership distributions	(74,283)	(74,283)
Common Units issued under Restricted Unit Plans	(1,761)	$ (1,761)
Common Units issued under Restricted Unit Plans (in units)		338
Compensation costs recognized under Restricted Unit Plans	4,822	$ 4,822
Balance, end of period at Mar. 28, 2020	471,322	$ 496,426	(25,104)
Balance (in units) at Mar. 28, 2020		62,073
Balance, beginning of period at Dec. 28, 2019	428,434	$ 454,079	(25,645)
Balance (in units) at Dec. 28, 2019		62,070
Net income	77,361	$ 77,361
Other comprehensive income	541		541
Partnership distributions	(37,242)	(37,242)
Common Units issued under Restricted Unit Plans	(32)	$ (32)
Common Units issued under Restricted Unit Plans (in units)		3
Compensation costs recognized under Restricted Unit Plans	2,260	$ 2,260
Balance, end of period at Mar. 28, 2020	$ 471,322	$ 496,426	$ (25,104)
Balance (in units) at Mar. 28, 2020		62,073