Accounts Receivable - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Amount billed but not received under retainage provisions in contracts	$ 1,100,000	$ 400,000
Retainage receivables on contracts period	P1Y
Provision for doubtful accounts	99,000	176,000
Accounts charged to the allowance	$ (35,000)	$ 200,000