Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Provision for Income Taxes	$ 7,392	$ 15,264	$ 30,327	$ 38,214
Effective Income Tax Rate Reconciliation, Percent	58.00%	38.00%	52.00%	36.00%
Increase (decrease) in deferred tax assets, changes in unrealized gain (loss) on marketable securities			$ 530	$ 60
Increase (decrease) in deferred tax assets, changes in foreign currency translation adjustments			$ 4,661	$ 1,737