Employee Benefit Plans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) Age	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Pension Plans, Defined Benefit | Sweden
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Defined contribution plan, company contribution	$ 485,000	$ 493,000	$ 437,000
Minimum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Defined contribution plan, eligible age of employees | Age	21
Defined Contribution 401 K Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Defined contribution plan, company contribution	$ 141,000	$ 107,000	$ 92,000