CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Unitholders [Member]	Accumulated Other Comprehensive (Loss) [Member]
Balance at Sep. 30, 2017	$ 552,982	$ 581,794	$ (28,812)
Balance (in units) at Sep. 30, 2017		61,105
Net income	37,168	$ 37,168
Other comprehensive income	757		757
Partnership distributions	(36,663)	(36,663)
Common Units issued under Restricted Unit Plans, net of units withheld for income tax withholding purposes	(846)	$ (846)
Common Units issued under Restricted Unit Plans, net of units withheld for income tax withholding purposes (in units)		284
Compensation costs recognized under Restricted Unit Plans	2,649	$ 2,649
Balance at Dec. 30, 2017	556,047	$ 584,102	(28,055)
Balance (in units) at Dec. 30, 2017		61,389
Balance at Sep. 29, 2018	493,824	$ 518,494	(24,670)
Balance (in units) at Sep. 29, 2018		61,405
Net income	27,719	$ 27,719
Other comprehensive income	552		552
Partnership distributions	(36,843)	(36,843)
Common Units issued under Restricted Unit Plans, net of units withheld for income tax withholding purposes	(1,349)	$ (1,349)
Common Units issued under Restricted Unit Plans, net of units withheld for income tax withholding purposes (in units)		259
Compensation costs recognized under Restricted Unit Plans	3,021	$ 3,021
Balance at Dec. 29, 2018	$ 486,924	$ 511,042	$ (24,118)
Balance (in units) at Dec. 29, 2018		61,664