Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value Based on Three-Tier Fair Value Hierarchy (Detail) - USD ($) $ in Thousands	Sep. 28, 2018	Dec. 31, 2017
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	$ 0
Total liabilities measured and recorded at fair value	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	5	$ 55
Total liabilities measured and recorded at fair value	195	4
Money market funds [Member] | Fair Value, Measurements, Recurring [Member] | Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value		22
Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	5	33
Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	195	4
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	0	22
Total liabilities measured and recorded at fair value	0	0
Level 1 [Member] | Money market funds [Member] | Fair Value, Measurements, Recurring [Member] | Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value		22
Level 1 [Member] | Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value		0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	5	33
Total liabilities measured and recorded at fair value	195	4
Level 2 [Member] | Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured and recorded at fair value	5	33
Level 2 [Member] | Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value	195	4
Level 3 [Member] | Fair Value, Measurements, Recurring [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
Level 3 [Member] | Foreign exchange forward contracts [Member] | Fair Value, Measurements, Recurring [Member] | Accrued Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured and recorded at fair value		$ 0