Cash and Cash Equivalents - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		113 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, money market accounts	$ 1,400,000		$ 1,400,000		$ 1,400,000
Percentage of interest recognized from money market fund	0.01%		0.01%		0.01%
Interest income	$ 59	$ 260	$ 195	$ 471	$ 1,358,612