Short-Term Debt - Additional Information (Detail) - Credit Facility [Member] - USD ($)			12 Months Ended
	Mar. 10, 2015	Aug. 14, 2014	Dec. 31, 2015	Dec. 31, 2014
Line of Credit Facility [Line Items]
Revolving line of credit	$ 15,000,000
Maturity period of credit facility	Mar. 10, 2017
Annual commitment fee	$ 100,000
Early termination fee in first year	1.00%
Early termination fee prior to maturity	0.25%
Borrowing interest rate			4.50%
Amount of outstanding credit facility			$ 0
PfG [Member]
Line of Credit Facility [Line Items]
Amount of outstanding credit facility		$ 0
Amount of penalties on Termination		$ 0
Maximum [Member]
Line of Credit Facility [Line Items]
Interest on short-term debt			$ 100,000	$ 100,000
Prime Rate [Member]
Line of Credit Facility [Line Items]
Variable interest rate	1.25%