Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value Based on Three-Tier Fair Value Hierarchy (Detail) (USD $)	Sep. 26, 2014		Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 0
Liabilities, Fair Value Disclosure, Nonrecurring	0
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	7,393,000		55,022,000
Total liabilities measured and recorded at fair value	0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	55,170,000		76,440,000
Total liabilities measured and recorded at fair value	331,000		195,000
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Total liabilities measured and recorded at fair value	0		0
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	62,563,000		131,462,000
Total liabilities measured and recorded at fair value	331,000		195,000
Cash equivalents [Member] | Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	4,292,000		51,014,000
Cash equivalents [Member] | Level 2 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Cash equivalents [Member] | Level 3 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Cash equivalents [Member] | Estimate of Fair Value Measurement [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	4,292,000		51,014,000
Short-term investments [Member] | Level 1 [Member] | State, municipal and local government agencies bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 1 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 1 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 1 [Member] | U.S. federal government bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value			4,008,000
Short-term investments [Member] | Level 2 [Member] | State, municipal and local government agencies bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	25,714,000		40,449,000
Short-term investments [Member] | Level 2 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	26,138,000		33,496,000
Short-term investments [Member] | Level 2 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	3,299,000		2,299,000
Short-term investments [Member] | Level 2 [Member] | U.S. federal government bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 3 [Member] | State, municipal and local government agencies bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 3 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 3 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Level 3 [Member] | U.S. federal government bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		0
Short-term investments [Member] | Estimate of Fair Value Measurement [Member] | State, municipal and local government agencies bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	25,714,000		40,449,000
Short-term investments [Member] | Estimate of Fair Value Measurement [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	26,138,000		33,496,000
Short-term investments [Member] | Estimate of Fair Value Measurement [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	3,299,000		2,299,000
Short-term investments [Member] | Estimate of Fair Value Measurement [Member] | U.S. federal government bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0		4,008,000
Prepaids and other current assets [Member] | Level 1 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0	[1]	0	[1]
Prepaids and other current assets [Member] | Level 2 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	19,000	[1]	196,000	[1]
Prepaids and other current assets [Member] | Level 3 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0	[1]	0	[1]
Prepaids and other current assets [Member] | Estimate of Fair Value Measurement [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	19,000	[1]	196,000	[1]
Other Long-term Investments [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	3,101,000
Other Long-term Investments [Member] | Level 1 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	3,101,000
Accrued Liabilities [Member] | Level 1 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	0	[1]	0	[1]
Accrued Liabilities [Member] | Level 2 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	331,000	[1]	195,000	[1]
Accrued Liabilities [Member] | Level 3 [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	0	[1]	0	[1]
Accrued Liabilities [Member] | Estimate of Fair Value Measurement [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	$ 331,000	[1]	$ 195,000	[1]

[1] Derivative assets and liabilities represent forward currency exchange contracts. The Company enters into these contracts to minimize the short-term impact of foreign currency exchange rates fluctuations primarily from trade and inter-company receivables and payables.