Business Acquisition - Summary of Final Allocation of Purchase Consideration, Including Contingent Consideration Payable, Based on Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014
Purchase consideration:
Cash		$ 5,000
Assets:
Goodwill	10,000	10,000
CureTech Ltd [Member]
Purchase consideration:
Cash	5,000	5,000
Acquisition-date fair value of contingent consideration	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