Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Summary Of Net Deferred Tax Assets [Line Items]
Deferred tax assets valuation allowance	$ 22,338,000	$ 23,939,000
Valuation allowance expiry year	2016
Accrued interest or penalties associated with unrecognized tax benefits	0
Minimum
Summary Of Net Deferred Tax Assets [Line Items]
Percentage of ownership change, limitations on utilization of net operating loss (NOL) and research and development (R&D) credit carry forwards	50.00%
Ownership change test period, limitations on utilization of net operating loss (NOL) and research and development (R&D) credit carry forwards	3 years
Domestic Tax Authority
Summary Of Net Deferred Tax Assets [Line Items]
Net federal operating loss	43,900,000
Net operating losses carry forwards, expiration year	2027
Research and development tax credit carry forward	600,000
State and Local Jurisdiction
Summary Of Net Deferred Tax Assets [Line Items]
Net federal operating loss	40,700,000
Net operating losses carry forwards, expiration year	2016
Research and development tax credit carry forward	$ 500,000