Restructuring and impairment charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		13 Months Ended	30 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 28, 2015
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 580	$ 7,623	$ 5,028	$ 15,403
Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	(12)	8,766	3,686	16,642
Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	267	(122)	359	254
Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	261	(1,223)	901	(1,695)
Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	64	202	82	202
2015 Restructuring Program
Restructuring Cost And Reserve [Line Items]
Restructuring charges	142		4,380
2015 Restructuring Program | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	9		3,559
2015 Restructuring Program | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	63		129
2015 Restructuring Program | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	24		645
2015 Restructuring Program | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	46		47
2014 Manufacturing Footprint Realignment
Restructuring Cost And Reserve [Line Items]
Restructuring charges	507	8,577	670	8,577
2014 Manufacturing Footprint Realignment | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	75	8,577	212	8,577
2014 Manufacturing Footprint Realignment | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	204	0	230	0
2014 Manufacturing Footprint Realignment | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	228	0	228	0
2014 Manufacturing Footprint Realignment | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	0	0	0
2014 European Restructuring Plan
Restructuring Cost And Reserve [Line Items]
Restructuring charges	18	(212)	43	8,106
2014 European Restructuring Plan | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	(566)	9	7,752
2014 European Restructuring Plan | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	0	0	0
2014 European Restructuring Plan | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	305	0	305
2014 European Restructuring Plan | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	18	49	34	49
2014 Restructuring Program
Restructuring Cost And Reserve [Line Items]
Restructuring charges		1,781	49	1,781	$ 3,600
2014 Restructuring Program | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges		476	0	476
2014 Restructuring Program | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0	0	0
2014 Restructuring Program | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		1,174	49	1,174
2014 Restructuring Program | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		131	0	131
LMA Restructuring Program
Restructuring Cost And Reserve [Line Items]
Restructuring charges	9	(2,942)	(20)	(3,372)		$ 11,300
LMA Restructuring Program | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	(29)	0	(29)
LMA Restructuring Program | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	(154)	0	(112)
LMA Restructuring Program | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	9	(2,759)	(21)	(3,231)
LMA Restructuring Program | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	0	1	0
2013 Restructuring Program
Restructuring Cost And Reserve [Line Items]
Restructuring charges	(96)	396	(94)	564		$ 11,000
2013 Restructuring Program | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges	(96)	317	(94)	485
2013 Restructuring Program | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	0	0	0
2013 Restructuring Program | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	57	0	57
2013 Restructuring Program | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 0	22	$ 0	22
2012 Restructuring Program
Restructuring Cost And Reserve [Line Items]
Restructuring charges		25		(265)
2012 Restructuring Program | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges		(9)		(619)
2012 Restructuring Program | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		34		354
2012 Restructuring Program | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0		0
2012 Restructuring Program | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0		0
2011 Restructuring Plan
Restructuring Cost And Reserve [Line Items]
Restructuring charges		(2)		12
2011 Restructuring Plan | Termination Benefits
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0		0
2011 Restructuring Plan | Facility Closure Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		(2)		12
2011 Restructuring Plan | Contract Termination Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		0		0
2011 Restructuring Plan | Other Exit Costs
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 0		$ 0