Income Taxes - Additional Information (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax And Carryforwards [Line Items]
Gross unrecognized tax benefits	$ 263,000	$ 260,000	$ 260,000
Unrecognized tax benefit, impact on effective tax rate	3,000
Interest and penalties	131,000
Federal
Income Tax And Carryforwards [Line Items]
Operating loss carryforwards	2,033,000
State
Income Tax And Carryforwards [Line Items]
Operating loss carryforwards	4,532,000
Tax credit carryforwards	1,245,000
Foreign
Income Tax And Carryforwards [Line Items]
Tax credit carryforwards	$ 328,000