Financial Instruments Measured at Fair Value - Derivatives (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Notional Amount		$ 340,445		$ 340,445		$ 401,048
Derivative, Fair Value, Net		3,514		3,514		1,072
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		3,392		3,392		962
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		$ 122		$ 122		110
3.375% notes, due 2015 [Member]
Derivatives, Fair Value [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.375%		3.375%
Notes Due in 2020 [Member]
Derivatives, Fair Value [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.00%		6.00%
Senior Debentures Due in 2018 [Member]
Derivatives, Fair Value [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.875%		6.875%
Interest Rate Swaps Converting Notes Due in 2015 [Member]
Derivatives, Fair Value [Line Items]
Notional Amount		$ 200,000		$ 200,000
Debt Instrument, Interest Rate, Stated Percentage		1.98%		1.98%
Cash received upon termination of 2015 swaps				$ 896
Derivative Instrument Gain (Loss) Reclassified into Income, Net		$ 29		68
Interest rate swaps designated as fair value hedges [Member] | Notes Due in 2020 [Member]
Derivatives, Fair Value [Line Items]
Notional Amount		50,000		50,000
Derivative, Fair Value, Net		$ 1,220		$ 1,220
Debt Instrument, Interest Rate, Effective Percentage		4.30%		4.30%
Interest rate swaps designated as fair value hedges [Member] | Senior Debentures Due in 2018 [Member]
Derivatives, Fair Value [Line Items]
Notional Amount		$ 50,000		$ 50,000
Derivative, Fair Value, Net		$ 566		$ 566
Debt Instrument, Interest Rate, Effective Percentage		5.72%		5.72%
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	[1]	$ 0	$ 0	$ 0	$ 0
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	[1]	0	0	0	0
Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	[2]	5,084	(376)	4,705	(148)
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	[2]	5,084	(376)	4,705	(148)
Foreign Exchange Contract [Member] | Other Current Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		2,002		2,002		2,404
Foreign Exchange Contract [Member] | Accrued Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(1,880)		(1,880)		(2,294)
Interest rate swaps designated as fair value hedges [Member] | Interest Rate Swap [Member] | Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		0		0		(3)
Interest rate swaps designated as fair value hedges [Member] | Interest Rate Swap [Member] | Other Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		1,786		1,786		381
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net	[3]	0	0	827	0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[3]	(144)	(165)	(446)	(489)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	[3]	0	0	69	0
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net	[4]	170	438	607	48
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[4]	(644)	(185)	(1,322)	(118)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	[4]	0	$ 0	0	$ 0
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Other Current Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		1,632		1,632		960
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Accrued Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(26)		(26)		$ (376)
Contingent Consideration [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Measurement Contingent Consideration-Current		3,704		3,704
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		$ 8,400		$ 8,400

[1] The amount of gain (loss) recognized in income on derivatives is recorded in "Interest and other financing expense, net" in the company's consolidated statements of operations.

[2] The amount of gain (loss) recognized in income on derivatives is recorded in "Cost of sales" in the company's consolidated statements of operations.

[3] Both the effective and ineffective portions of any gain (loss) reclassified or recognized in income are recorded in "Interest and other financing expense, net" in the company's consolidated statements of operations. The gain (loss) amounts reclassified into income relate to the termination of swaps.

[4] Both the effective and ineffective portions of any gain (loss) reclassified or recognized in income are recorded in "Cost of sales" in the company's consolidated statements of operations.