Business Acquisition - Summary of Final Allocation of Purchase Consideration, Including Contingent Consideration Payable, Based on Fair Value (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Assets:
Goodwill	$ 18,643	$ 10,000	$ 18,643
MDV3800 [Member]
Purchase consideration:
Cash	410,000		410,000
Acquisition-date fair value of contingent consideration	171,942		171,942
Total purchase consideration			581,942
Assets:
Identifiable intangible assets- IPR&D	573,299		573,299
Net identifiable assets acquired	573,299		573,299
Goodwill	8,643		8,643
Net assets acquired	581,942		581,942
MDV9300 [Member]
Purchase consideration:
Cash		5,000	5,000
Acquisition-date fair value of contingent consideration	106,000	$ 106,000	106,000
Total purchase consideration			111,000
Assets:
Identifiable intangible assets- IPR&D	101,000		101,000
Net identifiable assets acquired	101,000		101,000
Goodwill	10,000		10,000
Net assets acquired	$ 111,000		$ 111,000