Stock-Based Payment (Detail) - Stock option activity (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Outstanding at December 31, 2010	301,634	151,801
Outstanding at December 31, 2010 (in Dollars per share)	$ 18.57	$ 53.55
Granted	536,895	207,459
Granted (in Dollars per share)	$ 2.90	$ 5.35
Cancelled	(41,175)
Cancelled (in Dollars per share)	$ 3.06
Expired	(11,368)	(57,626)
Expired (in Dollars per share)	$ 78.97	$ 63.13
Outstanding at Ending Balance	785,986	301,634
Outstanding at Ending Balance (in Dollars per share)	$ 7.81	$ 18.57
Outstanding at Ending Balance	8 years 175 days	7 years 339 days
Outstanding at Ending Balance (in Dollars)
Exercisable at December 31, 2012	286,101
Exercisable at December 31, 2012 (in Dollars per share)	$ 15.98
Exercisable at December 31, 2012	7 years 3 months
Exercisable at December 31, 2012 (in Dollars)