Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Statutory Federal income tax rate	34.00%	34.00%	34.00%
Tax benefit related to stock compensation tax deductions	$ 7,509	$ 6,681	$ 1,831
Stock option exercises included in net operating loss carryforwards	13,643	5,525
Income tax holiday, amount of corporate income tax savings realized	33,965	33,545	24,102
Total unrecognized tax benefits	$ 4,486	4,443	$ 4,651	$ 2,241
Macedonia
Income Taxes [Line Items]
Income tax holiday, description	The government of Macedonia granted the Company a tax holiday that released the Company from the obligation to pay corporate income taxes for a ten year period, subject to certain limitations.
Income tax holiday, period	10 years
Income tax holiday, amount of corporate income tax savings realized	$ 0	0
Preferred Financing
Income Taxes [Line Items]
Net operating loss carryforward annual limitation	591
Net operating loss carryforward expected to expire	6,025
Net operating loss expired	13,324
U.S. Federal
Income Taxes [Line Items]
Stock option exercises included in net operating loss carryforwards	0	22,343
U.S. State
Income Taxes [Line Items]
Stock option exercises included in net operating loss carryforwards	$ 17,564	$ 17,213