Stockholders' Equity (Detail) (USD $) In Millions, except Share data, unless otherwise specified				6 Months Ended		0 Months Ended	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	May 21, 2012 Shelf Registration	Jun. 30, 2012 Minimum [Member] Purchase Agreement With LPC	Jun. 30, 2012 Maximum [Member] Purchase Agreement With LPC	Oct. 07, 2011 Purchase Agreement With LPC	Jun. 30, 2012 Purchase Agreement With LPC	Oct. 13, 2011 Purchase Agreement With LPC
Common Stock, Shares Authorized	24,000,000	24,000,000
Common Stock And Preferred Stock Shares Authorized	24,100,000
Common Stock, Par or Stated Value Per Share (in Dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	100,000	100,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share)	$ 0.01	$ 0.01
Stock Purchase Agreement Authorized Amount (in Dollars)			$ 50.0			$ 10.0	$ 10.0
Stock Purchase Agreement Period In Force						30 years	30 months
StockPurchase Agreement Number of Shares Registered								1,823,577
Stock Issued During Period Shares Issued As Commitment Fees							40,247
Stock Issued During Period Shares Issued As Additional Commitment Fees							80,494
Stock Purchase Agreement Remaining Number of Shares Authorized to be Sold							1,702,836
Sale of Stock, Maximum Sale Per Transaction (in Dollars)				0.5	1.5
Deferred Costs, Noncurrent (in Dollars)							$ 0.1