Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balances at Dec. 31, 2016					$ (83,283)
Net income	$ 60,418
Derivative instruments, net of tax	(3,044)
Pension and postretirement plans, net of tax	1,143
Balances at Apr. 22, 2017					(85,184)
Balances at Dec. 31, 2016					(83,283)
Balances at Dec. 30, 2017	$ 1,250,677	$ 199	$ 650,872	$ 919,658	(84,559)	$ (235,493)
Balances (in shares) at Dec. 30, 2017		228,729,585
Balances, treasury shares at Dec. 30, 2017	(18,203,381)					(18,203,381)
Net income	$ 51,247			51,247
Derivative instruments, net of tax	10,767				10,767
Pension and postretirement plans, net of tax	13,405				13,405
Exercise of stock options	791		(151)			$ 942
Exercise of stock options (in shares)						72,785
Amortization of share-based compensation awards	3,375		3,375
Issuance of deferred compensation			(37)			$ 37
Issuance of deferred compensation (in shares)						2,864
Performance-contingent restricted stock awards issued (Note 17)			(4,062)			$ 4,062
Performance-contingent restricted stock awards issued (in shares)						313,906
Issuance of deferred stock awards			(234)			$ 234
Issuance of deferred stock awards (in shares)						18,075
Stock repurchases	(2,489)					$ (2,489)
Stock repurchases (in shares)						(120,147)
Dividends paid on vested share-based payment awards	(405)			(405)
Dividends paid — $.1700 per common share	(35,837)			(35,837)
Reclassification of stranded income tax effects to retained earnings (Note 1)	18,800			18,806	(18,806)
Balances at Apr. 21, 2018	$ 1,291,531	$ 199	$ 649,763	$ 953,469	$ (79,193)	$ (232,707)
Balances (in shares) at Apr. 21, 2018		228,729,585
Balances, treasury shares at Apr. 21, 2018	(17,915,898)					(17,915,898)