Summary of Significant Accounting Policies (Property and Depreciation) (Details)	12 Months Ended
	Dec. 27, 2017
Building Assets [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Building Assets [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	30 years
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	10 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	15 years