Fair Value Measurements - Schedule of Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis (Detail) - Recurring Fair Value Measurements [Member] - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds, Balance	$ 61,193	$ 31,600
Contingent consideration payable, Balance	3,375	9,775
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds, Balance	61,193	31,600
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration payable, Balance	$ 3,375	$ 9,775