Fair Value Measurements (Tables)

9 Months Ended

Sep. 27, 2015

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured On Recurring Basis

	As of December 31, 2014
	Total		Quoted market prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents—money-market funds	$	4,408	$	4,408	$	—	$	—
Available-for-sale securities—U.S. treasuries (1)	114,935		114,935		—		—
Available-for-sale securities—certificates of deposit (1)	158		158		—		—
Trading securities—mutual funds (1)	802		802		—		—
Foreign currency forward contracts (2)	2,416		—		2,416		—
Total assets measured at fair value	$	122,719	$	120,303	$	2,416	$	—

(1) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.

(2) Included in prepaid expenses and other current assets on the Company’s unaudited condensed consolidated balance sheet.

	As of September 27, 2015
	Total		Quoted market prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents—money-market funds	$	45,904	$	45,904	$	—	$	—
Available-for-sale securities—U.S. treasuries (1)	60,093		60,093		—		—
Available-for-sale securities—certificates of deposit (1)	269		269		—		—
Trading securities—mutual funds (1)	1,057		1,057		—		—
Foreign currency forward contracts (2)	537		—		537		—
Total assets measured at fair value	$	107,860	$	107,323	$	537	$	—

(1) Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.

(2) Included in prepaid expenses and other current assets on the Company’s unaudited condensed consolidated balance sheet.

Fair Value, Liabilities Measured On Recurring Basis

	As of September 27, 2015
	Total		Quoted market prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Foreign currency forward contracts (3)	$	678	$	—	$	678	$	—
Total liabilities measured at fair value	$	678	$	—	$	678	$	—

(3) Included in other accrued liabilities on the Company’s unaudited condensed consolidated balance sheet.

	As of December 31, 2014
	Total		Quoted market prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Foreign currency forward contracts (3)	$	447	$	—	$	447	$	—
Total liabilities measured at fair value	$	447	$	—	$	447	$	—

(3) Included in other accrued liabilities on the Company’s unaudited condensed consolidated balance sheet.