Indebtedness - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Installment Loan	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Principal amount for notes payable	$ 5,000,000
Promissory Note payment terms	The promissory note with interest on the outstanding balance at the lowest short-term applicable federal rate per annum will be paid in two installments by July 15, 2015 and January 15, 2016.
Number of installments	2
Promissory Note outstanding balance first installment date	Jul. 15, 2015
Promissory Note outstanding balance second installment date	Jan. 15, 2016
Current portion of notes payable	2,492,000
Notes payable	2,262,000
Number of loans outstanding	2
Debt instrument interest rate	4.75%
Loan outstanding maturity date	2027-02
Loan unpaid principal balance	7,098,000
Total indebtedness of unpaid principal balance	1,600,000
Interest expenses on loans	100,000	100,000	100,000
Loan One [Member]
Debt Instrument [Line Items]
Loan unpaid principal balance	1,000,000
Loan Two [Member]
Debt Instrument [Line Items]
Loan unpaid principal balance	$ 600,000