Business, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Jun. 30, 2015 Segments	Dec. 31, 2017 USD ($) Segments Business_Lines	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jan. 01, 2018 USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segments	2	2
Cash equivalents, highly liquid investments original maturity date		Three months or less
Vendor rebates recorded as a reduction of inventory		$ 0	$ 359,000
Vendor rebates recorded as a reduction of cost of sales		$ 379,000	4,044,000
Percentage of employees eligible for severance benefits		98.00%
Recorded deferred revenue		$ 8,335,000	11,092,000
Advertising expense		$ 95,000	149,000	$ 144,000
Standard limited warranty period		The standard limited warranty period is one to two years for the majority of products.
Dividends		$ 0
Percentage of tax benefit realized upon settlement		50.00%
Other Current Assets [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Prepayments to suppliers		$ 7,404,000	1,390,000
Selling, General and Administrative Expenses [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Shipping and handling cost		$ 1,652,000	$ 1,631,000	$ 2,394,000
Minimum [Member] | Technology [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of Intangible assets		1 year
Minimum [Member] | Customer Relationships [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of Intangible assets		1 year
Maximum [Member] | Technology [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of Intangible assets		5 years
Maximum [Member] | Customer Relationships [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of Intangible assets		5 years
Maximum [Member] | Intellectual Property Assets [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of Intangible assets		10 years
Maximum [Member] | Accounting Standards Update 2014-09 [Member] | Subsequent Event [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Adjustment to increase the equity					$ 10,000,000
Standard Products Group [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of business lines | Business_Lines		2