Line of Credit - Additional Information (Detail) - USD ($)		12 Months Ended
	Apr. 22, 2014	Dec. 31, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Revolving line of credit, permitted		$ 25,000,000
Line of credit, maturity date		Jun. 30, 2017
Term facility payable (in years)		Five
Interest paid on basis points		Prime Rate plus 50 basis points or LIBOR plus 250 basis points.
Percentage of restricted dividend payments		55.00%
Line of credit		$ 0	$ 0
Percentage of stock dividend declared	100.00%
Prime Rate [Member]
Line of Credit Facility [Line Items]
Interest rate spread above benchmark rate		0.50%
LIBOR [Member]
Line of Credit Facility [Line Items]
Interest rate spread above benchmark rate		2.50%
Minimum [Member]
Line of Credit Facility [Line Items]
Percentage of stock dividend declared		37.00%
Maximum [Member]
Line of Credit Facility [Line Items]
Percentage of stock dividend declared		53.00%