Computation of Diluted Net Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended		150 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012
Basic and diluted net loss per common share:
Net loss	$ (9,675)	$ (10,915)	$ (71,992)
Preferred stock dividends	(976)	(1,568)	(4,235)
Preferred stock accretion	(230)	(230)	(4,045)
Net loss applicable to common stockholders	$ (10,881)	$ (12,713)	$ (80,272)
Weighted average common shares outstanding-basic and diluted	15,131	11,986
Net loss per common share-basic and diluted	$ (0.72)	$ (1.06)