Goodwill and Other Intangible Assets Gross Carrying Amount and Accumulated Amoritzation of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Goodwill [Line Items]
Goodwill, gross	$ 1,443,829	$ 1,326,077	$ 1,235,701
Acquisitions
Transfers
Foreign Exchange
Goodwill	$ 438,829	$ 321,077	230,701
RMS
Goodwill [Line Items]
Goodwill, gross	58,167	59,196	83,551
Acquisitions	0	0
Transfers		(23,172)
Foreign Exchange	(1,029)	(1,183)
DSA
Goodwill [Line Items]
Goodwill, gross	1,252,050	1,234,302	1,152,150
Acquisitions	22,146	102,171
Transfers		(9,196)
Foreign Exchange	(4,398)	(10,823)
Accumulated impairment loss	(1,005,000)	(1,005,000)	(1,005,000)
Manufacturing
Goodwill [Line Items]
Goodwill, gross	133,612	32,579	$ 0
Acquisitions	105,567	0
Transfers		32,368
Foreign Exchange	$ (4,534)	$ 211