Pension Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 24, 2016	Dec. 26, 2015	Sep. 24, 2016
Components of net periodic benefit costs included in operating expenses [Abstract]
Contribution to defined pension benefit plan	$ 1,396	$ 0
Estimated obligation due to withdrawal multi employer pension plans	23,591		$ 24,205
Defined Benefit Pension Plan [Member]
Components of net periodic benefit costs included in operating expenses [Abstract]
Defined pension benefit plan expected contribution to be paid for the remainder of fiscal year	10,704
Contribution to defined pension benefit plan	1,396
Post-Retirement Benefits [Member]
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	922
Employer contribution for postretirement health care and life insurance	$ 233