Summary of Geographic Information Related to Company's Total Revenues and Long Lived Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,464	$ 1,646	$ 4,335	$ 4,797
Percentage of total revenue			100.00%	100.00%
Long-lived assets	7,247		7,247		8,276
Percentage of long-lived assets	100.00%		100.00%		100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			4,210	4,797
Percentage of total revenue			97.00%	100.00%
Long-lived assets	7,223		7,223		8,276
Percentage of long-lived assets	100.00%		100.00%		100.00%
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			125
Percentage of total revenue			3.00%	0.00%
Long-lived assets	24		24
Percentage of long-lived assets	0.00%		0.00%		0.00%
Total International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			125
Percentage of total revenue			3.00%	0.00%
Long-lived assets	$ 24		$ 24
Percentage of long-lived assets	0.00%		0.00%		0.00%