Pension Plans and Other Postretirement Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 28, 2015	Mar. 29, 2014	Mar. 28, 2015	Mar. 29, 2014
Components of net periodic benefit costs included in operating expenses [Abstract]
Projected annual contribution requirements related to the Partnership's postretirement health care and life insurance benefit plan for fiscal year			$ 1,276
Employer contribution for postretirement health care and life insurance			460
Partnership established accrual for estimated obligation to certain MEPPs	6,821		6,821
Number of voluntary partial withdrawal from multi employer pension plans			1
Number of full withdrawal from multi employer pension plans			4
Pension Benefits [Member]
Components of net periodic benefit costs included in operating expenses [Abstract]
Interest cost	1,282	1,443	2,564	2,887
Expected return on plan assets	(1,228)	(1,275)	(2,457)	(2,551)
Amortization of net loss (gain)	1,131	1,123	2,261	2,246
Net periodic benefit cost	1,185	1,291	2,368	2,582
Postretirement Benefits [Member]
Components of net periodic benefit costs included in operating expenses [Abstract]
Interest cost	143	161	288	323
Amortization of prior service costs	(123)	(122)	(245)	(245)
Amortization of net loss (gain)	(49)	(46)	(98)	(91)
Net periodic benefit cost	$ (29)	$ (7)	$ (55)	$ (13)