Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 150,120	$ 163,776	$ 189,191
Pension and postretirement plans:
Settlement loss	3,072	4,087
Net loss for the period	(2,637)	(4,013)	(2,537)
Amortization of prior service credit included in net income	108	108	(164)
Amortization of actuarial loss included in net income	3,603	4,206	2,703
Pension and postretirement plans, net of tax	4,146	4,388	2
Derivative instruments:
Net change in fair value of derivatives	(6,789)	5,730	(4,195)
Loss reclassified to net income	1,367	3,399	5,413
Derivative instruments, net of tax	(5,422)	9,129	1,218
Other comprehensive income (loss), net of tax	(1,276)	13,517	1,220
Comprehensive income	$ 148,844	$ 177,293	$ 190,411