Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Unrecognized tax benefits, reduced	$ 641,000	$ 641,000
Allowed percentage by the IRS appeal group for research and development tax credit	100.00%
Unrecognized tax benefits, accrued interest	21,000	26,000	77,000
Unrecognized tax benefits, net interest benefit	$ 5,400	$ 51,000	$ 7,000