Schedule of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands		Jul. 02, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Marketable securities		$ 1,021,839	$ 1,304,867
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		598,349	307,884
Marketable securities		1,021,839	1,304,867
Derivative assets		23	1
Contingent consideration		39,415	38,332
Derivative liabilities		304	131
Convertible debt	[1]	526,976	486,754
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		598,349	307,884
Marketable securities		1,021,839	1,304,867
Derivative assets		23	1
Contingent consideration		39,415	38,332
Derivative liabilities		304	131
Convertible debt	[1]	$ 359,245	$ 352,669

[1] The carrying value represents the bifurcated debt component only, while the fair value is based on quoted market prices for the convertible note which includes the equity conversion features.