Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 05, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 1,051,941us-gaap_AvailableForSaleSecurities	$ 1,004,576us-gaap_AvailableForSaleSecurities
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	427,119	402,154
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	232,187	258,502
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	160,877	141,467
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	130,298	140,638
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	87,052	49,036
Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	13,962	12,333
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	446	446
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total including derivatives	1,270,886	1,298,832
Available for sale securities	1,270,886
Contingent consideration	3,350	3,350
Derivatives	19	149
Total	3,369	3,499
Fair Value, Measurements, Recurring \| Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	115,982	111,471
Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	102,963	182,785
Fair Value, Measurements, Recurring \| U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	427,119	402,154
Fair Value, Measurements, Recurring \| U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	232,187	258,502
Fair Value, Measurements, Recurring \| Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	160,877	141,467
Fair Value, Measurements, Recurring \| Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	130,298	140,638
Fair Value, Measurements, Recurring \| Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	87,052	49,036
Fair Value, Measurements, Recurring \| Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	13,962	12,333
Fair Value, Measurements, Recurring \| Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	446	446
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total including derivatives	230,738	284,022
Available for sale securities	230,738
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	115,982	111,471
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	100,794	160,218
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	13,962	12,333
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total including derivatives	1,040,148	1,014,810
Available for sale securities	1,040,148
Derivatives	19	149
Total	19	149
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	2,169	22,567
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	427,119	402,154
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	232,187	258,502
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	160,877	141,467
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	130,298	140,638
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	87,052	49,036
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	446	446
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	3,350	3,350
Total	$ 3,350	$ 3,350

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value of financial and nonfinancial obligations.

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