Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 164,538	$ 157,160	$ 150,120
Pension and postretirement plans:
Settlement loss		5,816	3,072
Net actuarial loss for the period	(8,000)	(19,831)	(2,637)
Amortization of prior service cost included in net income	259	130	108
Amortization of actuarial loss included in net income	5,099	4,022	3,603
Pension and postretirement plans, net of tax	(2,642)	(9,863)	4,146
Derivative instruments:
Gain (loss) on effective portion of derivatives	8,457	2,978	(6,789)
(Gain) loss reclassified to net income	(2,664)	1,079	1,367
Derivative instruments, net of tax	5,793	4,057	(5,422)
Other comprehensive income (loss), net of tax	3,151	(5,806)	(1,276)
Comprehensive income	$ 167,689	$ 151,354	$ 148,844

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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