Commitments and Contingencies - Additional Information (Detail) $ in Thousands, € in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) $ / €	Mar. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)	[1]
Commitments and Contingencies [Line Items]
Contingent payments upon achievement of certain development and regulatory activities and commercial sales and licensing milestones	$ 581,800
Contingent consideration payable	161,700
Short-term contingent acquisition consideration payable	45,264		$ 46,327
Purchase commitment for the next five years	94,400
Merck Serono
Commitments and Contingencies [Line Items]
Contingent payments upon achievement of certain development and regulatory activities and commercial sales and licensing milestones	$ 198,000	€ 185
Currency exchange translation rate | $ / €	1.07
Completed Programs
Commitments and Contingencies [Line Items]
Contingent payments upon achievement of certain development and regulatory activities and commercial sales and licensing milestones	$ 51,000

[1] December 31, 2016 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016, filed with the Securities and Exchange Commission (the SEC) on February 27, 2017.