Schedule of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 4,887	$ 5,818
Accumulated amortization	(1,768)	(1,541)
Intangible assets, net	3,119	4,277
Product Licensing Rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,311	3,156
Accumulated amortization	(1,768)	(1,541)
Intangible assets, net	1,543	1,615
Product Development Rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,576	2,662
Intangible assets, net	$ 1,576	$ 2,662