Employee Benefit Plans (Schedule Of Accrued Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Accrued pensions — current	$ 3,994	$ 4,472
Accrued pensions	86,554	108,920
Net amount recognized at end of year	90,548	113,392
Other comprehensive income attributable to prior service cost arising during year	(240)	(306)
Accumulated benefit obligation at end of year	$ 88,442	$ 110,204