Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Valuation allowance, deferred tax asset, change in amount	$ 9,800,000
Operating loss carry forwards	74,566,000	$ 64,300,000
Unrecognized tax benefits	1,363,000	1,202,000	$ 1,048,000	$ 862,000
Accrued interest or penalties related to uncertain tax positions	$ 0	$ 0
Statutory income tax rate	21.00%	34.00%	34.00%
Decrease in deferred tax assets due to newly enacted tax rate		$ 36,100,000
Decrease in valuation allowance due to newly enacted tax rate		36,100,000
GILTI deferred amounts		$ 0
GILTI income tax	$ 0
Domestic Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating loss carry forwards	290,900,000
Operating loss carryforwards subject to expiration	$ 254,500,000
Operating loss carryforwards expiration period	2027
Remaining operating loss carryforwards	$ 36,400,000
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Operating loss carry forwards	234,600,000
Operating loss carryforwards subject to expiration	$ 231,700,000
Operating loss carryforwards expiration period	2022
Remaining operating loss carryforwards	$ 2,900,000
Foreign Tax Authority [Member] | Italy
Income Tax Contingency [Line Items]
Operating loss carry forwards	19,400,000
Foreign Tax Authority [Member] | Luxembourg [Member]
Income Tax Contingency [Line Items]
Operating loss carry forwards	$ 200,000
Foreign Tax Authority [Member] | Switzerland [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards expiration period	2023
Operating loss carry forwards	$ 24,100,000
Foreign Tax Authority [Member] | Japan [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards expiration period	2028
Operating loss carry forwards	$ 800,000
Research Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax credit carry forward, amount	$ 6,200,000
Tax credit carry forward expiration period	2027