Financial instruments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 25, 2016	Sep. 27, 2015	Sep. 25, 2016	Sep. 27, 2015	Dec. 31, 2015
Derivatives Fair Value [Line Items]
Allowance for doubtful accounts receivable	$ 9,000,000		$ 9,000,000		$ 8,000,000
Current portion of allowance for doubtful accounts	2,100,000		2,100,000		2,000,000
Noncurrent portion of allowance for doubtful accounts	6,900,000		6,900,000		6,000,000
Net revenues	455,648,000	$ 443,714,000	1,354,094,000	$ 1,325,189,000
Spain, Italy, Portugal, and Greece
Derivatives Fair Value [Line Items]
Allowance for doubtful accounts receivable	8,000,000		8,000,000		7,200,000
Net revenues			95,800,000	94,400,000
Cash flow hedging
Derivatives Fair Value [Line Items]
Ineffectiveness related to derivatives	0	$ 0	$ 0	$ 0
Designated as Hedging Instrument | Cash flow hedging | Foreign Currency Contract
Derivatives Fair Value [Line Items]
Derivative duration			9 months
Forward Contracts | Designated as Hedging Instrument | Cash flow hedging | Foreign Currency Contract
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts	100,100,000		$ 100,100,000		49,500,000
Forward Contracts | Not Designated as Hedging Instrument | Foreign Currency Contract
Derivatives Fair Value [Line Items]
Loss related to currency forward contracts	100,000		1,700,000
Total notional amount for all open foreign currency forward contracts	$ 77,400,000		$ 77,400,000		$ 69,100,000