Disposal of Video Camera Segment - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended
	Jun. 06, 2014	Sep. 27, 2014	Jun. 28, 2014	Sep. 27, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received from sale of video camera segment	$ 9,500,000			$ 9,886,000
Divestiture-related costs		0	800,000
Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration from sale of video camera segment	$ 500,000