Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Statutory Federal income tax rate	34.00%	34.00%	34.00%
Tax benefit related to stock compensation tax deductions	$ 6,681	$ 1,831	$ 2,074
Stock option exercises included in net operating loss carryforwards	5,525	7,075
Total unrecognized tax benefits	$ 4,443	$ 4,651	$ 2,241	$ 2,191
Macedonia
Income Taxes [Line Items]
Income tax holiday, expiration period	expire no later than 2025
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	$ 22,343