Goodwill and Intangible Assets, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition [Line Items]
Impairment charge	$ 0	$ 0	$ 0
Hermes Bio Sciences Inc [Member]
Business Acquisition [Line Items]
Acquired IPR&D recognized in a business combination	7.0
Amortization period	10 years
Impairment charge	0.8
Hermes Bio Sciences Inc [Member] | Core Nano Carrier Technology [Member]
Business Acquisition [Line Items]
Acquired intangible assets	3.2
Hermes Bio Sciences Inc [Member] | Antibody Targeted Nanotherapeutic Program with Chemotherapy Drug [Member]
Business Acquisition [Line Items]
Acquired IPR&D recognized in a business combination	2.8
Hermes Bio Sciences Inc [Member] | Nanotherapeutic Program with Chemotherapy Drug [Member]
Business Acquisition [Line Items]
Acquired IPR&D recognized in a business combination	3.4
Hermes Bio Sciences Inc [Member] | Other Inprocess Research and Development Program [Member]
Business Acquisition [Line Items]
Acquired IPR&D recognized in a business combination	$ 0.8