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	$ 105,158
Derivative instruments, net of tax	4,514
Pension and postretirement plans, net of tax	2,001
Balances at Jul. 15, 2017					(76,768)
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	$ 96,689			96,689
Derivative instruments, net of tax	2,084				2,084
Pension and postretirement plans, net of tax	19,021				19,021
Exercise of stock options	791		(151)			$ 942
Exercise of stock options (in shares)						72,785
Amortization of share-based compensation awards	5,450		5,450
Issuance of deferred compensation			(121)			$ 121
Issuance of deferred compensation (in shares)						9,298
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			(1,054)			$ 1,054
Issuance of deferred stock awards (in shares)						81,255
Stock repurchases	(2,489)					$ (2,489)
Stock repurchases (in shares)						(120,147)
Dividends paid on vested share-based payment awards	(492)			(492)
Dividends paid — $.3500 per common share	(73,796)			(73,796)
Reclassification of stranded income tax effects to retained earnings (Note 1)	18,800			18,806	(18,806)
Balances at Jul. 14, 2018	$ 1,297,935	$ 199	$ 650,934	$ 960,865	$ (82,260)	$ (231,803)
Balances (in shares) at Jul. 14, 2018		228,729,585
Balances, treasury shares at Jul. 14, 2018	(17,846,284)					(17,846,284)