Acquisitions (Narrative) (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Sep. 16, 2013 USD ($) employee	Jun. 27, 2015 USD ($)	Jun. 28, 2014 USD ($)	Jun. 27, 2015 USD ($)	Jun. 28, 2014 USD ($)
Business Acquisition [Line Items]
Acquisition related costs		$ 100	$ 1,100	$ 300	$ 3,100
National Envelope Acquisition [Member]
Business Acquisition [Line Items]
Number of employees (employee) | employee	1,600
Acquisition purchase price	$ 34,062
Acquistion purchase price, company common stock	6,000
Gain on bargain purchase	17,262
Gain on bargain purchase, tax expense	6,800
Finite-lived intangible assets	4,430
Leasehold interests [Member] | National Envelope Acquisition [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets	$ 4,400
Intangible asset, useful life (years)	20 years