Fair Value Measurements (Summary of Valuation of Company's Financial Instruments by Various Levels) (Details) - USD ($) $ in Thousands		Sep. 27, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		$ 168,002	$ 27,755
Liabilities measured at fair value		7,691	6,453
Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		166,366	26,128
Liabilities measured at fair value		0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		310	301
Liabilities measured at fair value		1,488	525
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		1,326	1,326
Liabilities measured at fair value		6,203	5,928
Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		161,518	22,105
Cash equivalents | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		161,518	22,105
Cash equivalents | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Cash equivalents | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		0	0
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	151	149
Certificates of deposit | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Certificates of deposit | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	151	149
Certificates of deposit | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Trading securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	4,848	4,023
Trading securities | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	4,848	4,023
Trading securities | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Trading securities | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Convertible debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	1,326	1,326
Convertible debt | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Convertible debt | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	0	0
Convertible debt | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[1]	1,326	1,326
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	159	152
Liabilities measured at fair value	[3]	1,488	525
Foreign currency forward contracts | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Liabilities measured at fair value	[3]	0	0
Foreign currency forward contracts | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	159	152
Liabilities measured at fair value	[3]	1,488	525
Foreign currency forward contracts | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	[2]	0	0
Liabilities measured at fair value	[3]	0	0
Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[4]	6,203	5,928
Contingent Consideration | Quoted market prices in active markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[4]	0	0
Contingent Consideration | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[4]	0	0
Contingent Consideration | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	[4]	$ 6,203	$ 5,928

[1] ^{Included in Short-term investments on the Company’s unaudited condensed consolidated balance sheets.}

[2] ^{Included in Prepaid expenses and other current assets on the Company’s unaudited condensed consolidated balance sheets.}

[3] ^{Included in Other accrued liabilities on the Company’s unaudited condensed consolidated balance sheets.}

[4] ^{Included in Other non-current accrued liabilities on the Company’s unaudited condensed consolidated balance sheets. The contingent consideration represents the estimated fair value of the additional variable cash consideration payable in connection with the acquisition of Meural in August 2018 that is contingent upon the achievement of certain technical and service revenue milestones. As of September 27, 2020 and December 31, 2019, there were no material changes in the range of expected outcomes and the fair value of the contingent consideration from the acquisition date.}