Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Taxes [Line Items]
Income tax provision	$ 30,647	$ 19,350	$ 62,706	$ 36,377
Effective income tax rate, percentage	25.80%	30.70%	28.30%
Acquired in-process research and development	$ 0	$ 0	$ 0	$ 127,000
Non-Taxable Jurisdiction [Member]
Income Taxes [Line Items]
Modified effective income tax rate, percentage				32.10%
Ireland [Member]
Income Taxes [Line Items]
Effective statutory income tax rate, percentage	12.50%		12.50%