Employee Benefit Plans (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Service cost	$ 1,194	$ 1,097	$ 1,081
Interest cost	2,106	3,555	3,537
Expected return on plan assets	(134)	(1)	103
Amortization of actuarial loss	2,947	1,495	1,567
Amortization of prior service costs	26	12	2
Net periodic pension cost	6,139	6,158	6,290
Total pension expense	$ 6,139	$ 6,158	$ 6,290