Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Deferred tax asset valuation allowance	$ 24,552,000	$ 26,842,000
Tax credit carryforwards	$ 2,700,000
Tax credit carryforwards expiration period	2018
Period of increase in ownership	3 years
Japan [Member]
Operating Loss Carryforwards [Line Items]
Increase in valuation allowance against deferred tax assets warranted	$ 100,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	54,400,000
Domestic Tax Authority [Member] | Expire in 2022 and 2023 [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 36,400,000
Domestic Tax Authority [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration period	2022
Domestic Tax Authority [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration period	2023
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 1,600,000
Expired state net operating losses	$ 200,000
Operating loss carryforwards expiration period	2017