Retirement Plans (Retirement Plan Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ 3,162	$ 5,171	$ 5,794
Retirement savings plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	3,161	3,010	3,465
Deferred compensation plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	(318)	1,328	126
Supplemental executive retirement plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	484	1,061	2,025
Deferred compensation plan for pharmacists [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ (165)	$ (228)	$ 178