Property and Equipment, Net (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 26, 2014	Sep. 27, 2013	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 521,043,000		$ 521,043,000		$ 502,104,000
Accumulated depreciation	(323,830,000)		(323,830,000)		(297,962,000)
Property and equipment, net	197,213,000		197,213,000		204,142,000
Depreciation Expense	11,900,000	10,800,000	37,100,000	31,200,000
Land and land rights [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	23,157,000		23,157,000		23,157,000
Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	159,858,000		159,858,000		159,123,000
Equipment and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	291,465,000		291,465,000		281,197,000
Office furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,646,000		24,646,000		24,438,000
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,345,000		12,345,000		12,391,000
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,572,000		$ 9,572,000		$ 1,798,000