Business Combinations and Contingent Consideration - Summary of Allocation of Total Purchase Price to Net Assets Acquired (Detail) (Captisol-enabled, propylene glycol-free melphalan rights [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015
Business Acquisition, Contingent Consideration [Line Items]
Total purchase consideration	$ 7,700
In-process research and development [Member]
Business Acquisition, Contingent Consideration [Line Items]
Total purchase consideration	$ 7,700