Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 24, 2016	Jun. 30, 2017	Jun. 24, 2016
Statement of Comprehensive Income [Abstract]
Net Earnings	$ 79,828	$ 50,947	$ 140,560	$ 90,499
Components of other comprehensive income (loss)
Cumulative translation adjustment	11,029	(7,635)	17,347	(10,037)
Pension and postretirement medical liability adjustment	1,784	1,777	3,784	3,250
Income taxes - pension and postretirement medical liability adjustment	(717)	(635)	(1,483)	(1,204)
Other comprehensive income (loss)	12,096	(6,493)	19,648	(7,991)
Comprehensive Income	$ 91,924	$ 44,454	$ 160,208	$ 82,508