Debt and Subsequent Event - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Compensating balance amount	$ 0
Commercial Loan [Member]
Debt Instrument [Line Items]
Variable rate interest	LIBOR
Variable rate interest Option 2	One and one half percent over the thirty, sixty or ninety day London Interbank Offered Rate ("LIBOR").
Commitment fee amount	0
Compensating balance amount	0
Commercial bank loan	5,000,000
Debt instrument maturity term	10 years
Amortization period	20 years
loan Interest rate	4.11%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Extended revolving line of credit facility	5,000,000
Line of credit facility maturity date	Jun. 25, 2015
Variable rate interest	LIBOR
Variable rate interest Option 2	One and three-quarters percent over the thirty, sixty or ninety day London Interbank Offered Rate ("LIBOR") with a LIBOR floor of one and one-quarter percent.
Commitment fee amount	0
Outstanding line of credit	$ 0	$ 0