Financial instruments - additional information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014	Dec. 31, 2014
Derivatives Fair Value [Line Items]
Amount of losses in accumulated other comprehensive income to be reclassified as expense to the statement of income	$ 200,000		$ 200,000
Allowance for Doubtful Accounts Receivable	8,900,000		8,900,000		$ 8,800,000
Current portion of allowance for doubtful accounts	2,300,000		2,300,000		2,400,000
Noncurrent portion of allowance for doubtful accounts	6,600,000		6,600,000		6,400,000
Net revenues	443,714,000	$ 457,173,000	1,325,189,000	$ 1,363,824,000
Spain, Italy, Portugal, and Greece
Derivatives Fair Value [Line Items]
Allowance for Doubtful Accounts Receivable	7,900,000		7,900,000		8,100,000
Net revenues			94,400,000	114,800,000
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 Forward Contract
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts	49,800,000		$ 49,800,000		$ 0
Derivative duration			9 months
Not Designated as Hedging Instrument | Foreign Currency Forward Contract
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts	77,600,000		$ 77,600,000
Loss related to currency forward contracts	$ 300,000		$ 300,000