Long Term Debt - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Debt instrument interest rate	4.75%
Loan outstanding maturity date	2027-02
Loan unpaid principal balance	$ 1,757,000
Interest expenses on loans	86,000	90,000	94,000
Loan One
Debt Instrument [Line Items]
Loan unpaid principal balance	1,117,000
Loan Two
Debt Instrument [Line Items]
Loan unpaid principal balance	$ 640,000