Pension Plans and Other Postretirement Benefits (Tables)

9 Months Ended

Jun. 30, 2018

Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]

Components of Net Periodic Benefit Costs

The following table provides the components of net periodic benefit costs:

	Pension Benefits
	Three Months Ended						Nine Months Ended
	June 30,			June 24,			June 30,			June 24,
	2018			2017			2018			2017
Interest cost	$	944		$	1,041		$	2,832		$	3,123
Expected return on plan assets		(473	)		(537	)		(1,420	)		(1,611	)
Amortization of net loss		920			1,301			2,762			3,901
Net periodic benefit cost	$	1,391		$	1,805		$	4,174		$	5,413

	Postretirement Benefits
	Three Months Ended						Nine Months Ended
	June 30,			June 24,			June 30,			June 24,
	2018			2017			2018			2017
Interest cost	$	69		$	96		$	208		$	288
Amortization of prior service credits		(124	)		—			(374	)		—
Amortization of net (gain)		(163	)		(98	)		(491	)		(292	)
Net periodic benefit cost	$	(218	)	$	(2	)	$	(657	)	$	(4	)