Organization and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($) Segment Depository Source	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2012
Summary Of Significant Accounting Policy [Line Items]
Impairment losses	$ 0	$ 0	$ 0
Number of revenue sources | Source	2
Service term for services purchased	1 year
Accounts and notes receivable related to purchases		0
Advertising cost	$ 400,000	600,000	300,000
Warranty period	1 year
Research and development costs	$ 30,609,000	23,614,000	$ 14,885,000
Allowance for doubtful accounts	$ 443,000	$ 322,000
Number of depository institutions | Depository	5
Aggregate balances in depository institution accounts	$ 33,200,000
Percentage of total net sales represented	10.00%	10.00%	10.00%
Accounts and notes receivable by customers one	14.50%	12.50%
Cash surrender value of corporate-owned life insurance policies (Note 1)	$ 3,240,000	$ 2,180,000
Number of reportable segments of company | Segment	2
Minimum
Summary Of Significant Accounting Policy [Line Items]
Service term for services purchased	1 year			3 years
Maximum
Summary Of Significant Accounting Policy [Line Items]
Service term for services purchased	5 years			5 years
Extended Product Warranty
Summary Of Significant Accounting Policy [Line Items]
Service term for services purchased	5 years	5 years
Extended Product Warranty | Minimum
Summary Of Significant Accounting Policy [Line Items]
Period of extended warranty after expiration of standard warranty	1 year
Extended Product Warranty | Maximum
Summary Of Significant Accounting Policy [Line Items]
Period of extended warranty after expiration of standard warranty	5 years
Evidence. Com
Summary Of Significant Accounting Policy [Line Items]
Service term for services purchased		2 years 6 months