Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Increase in valuation allowance	$ 456
Deferred income tax assets	24,633	$ 25,419
Net operating loss associated with excess benefits related to stock compensation	9,600
Accrued interest or penalties related to uncertain tax positions	82
Lapse of statute of limitations	282
Total amount of unrecognized tax benefits	2,300
Canada | Research and Development
Income Taxes [Line Items]
Tax credit carryforwards	$ 1,600
Tax credit carryforward expiration year	2035
Domestic Tax Authority
Income Taxes [Line Items]
Net operating loss carryforwards	$ 31,900
Net operating losses expiration beginning period	2028
Federal net operating losses expiration ending Period	2033
Tax credit carryforwards	$ 9,800
Federal credit carryforward expiration, beginning period	2016
Federal credit carryforward expiration ending Period	2035
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards	$ 52,300
Net operating losses expiration beginning period	2028
Tax credit carryforwards	$ 1,400
Foreign Tax Authority | Ireland
Income Taxes [Line Items]
Net operating loss carryforwards	3,000
New Accounting Principles, Early Adoption, Effect
Income Taxes [Line Items]
Deferred income tax assets	$ 2,900