Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accounting Policies [Abstract]
Impairment of investments			$ 0
Based on these sales prices reduced inventory and increased cost of goods sold	354,000	107,000	1,500,000	421,000
Reduced inventory and increased costs of goods sold	363,000	46,000	363,000	255,000
Impairment of property plant and equipment			0
Revenue recorded from government contract	272,000	110,000	397,000	208,000
Period of contract			3 years
Total value of the contract	4,700,000		4,700,000
Value of contract recognized			$ 3,100,000