Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Income Taxes And Tax Related [Line Items]
Statutory federal income tax rate	34.00%
Net operating loss carryforwards	$ 92.6
Research and development tax credit carryforwards	$ 2.2
Open for examination	2004
Minimum [Member]
Income Taxes And Tax Related [Line Items]
Operating loss carryforwards expiration year	2023
Maximum [Member]
Income Taxes And Tax Related [Line Items]
Operating loss carryforwards expiration year	2033