Restructuring and Other - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 28, 2014	Sep. 28, 2014 Severance and Benefits	Sep. 28, 2014 Wireless Test Employee	Sep. 29, 2013 System Test and Semiconductor Test Employee	Sep. 29, 2013 System Test	Sep. 29, 2013 Semiconductor Test	Sep. 29, 2013 Corporate And Eliminations
Restructuring Cost and Reserve
Severance benefit and charges				$ 800,000	$ 1,500,000	$ 1,400,000	$ 400,000
Reduction in employees head count				30	40
Change in estimated exit costs related to leased facility								(400,000)
Accrual balance for severance and benefits	210,000	210,000	210,000
Changes to fair value of contingent consideration	$ 630,000	$ 630,000