Summary of Debt (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Jan. 24, 2013
Debt Instrument [Line Items]
Total debt	$ 89,603	$ 92,218
Fair value of embedded derivative	3,680	5,914
Unamortized debt discount	(4,229)	(4,610)
Current portion of debt	(55)	(65)
Long-term portion of debt	88,999	93,457
Equipment note
Debt Instrument [Line Items]
Total debt	55	70
Maturity Date	January 2015
HSBC Facility
Debt Instrument [Line Items]
Total debt	10,369	10,369
Maturity Date	May 2016
Secured and unsecured debt
Debt Instrument [Line Items]
Total debt	10,424	10,439
Convertible Senior Subordinated Notes
Debt Instrument [Line Items]
Total debt	79,179	81,779
Unamortized debt discount			$ (5,300)
Maturity Date	February 2018