Stock-Based Compensation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017 USD ($) Plan shares	Mar. 31, 2016 USD ($) shares	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | Plan	2
Shares outstanding under equity incentive plans	1,075,000		1,075,000
Expense related to options granted under equity incentive plan | $	$ 40,000	$ 77,000
Stock options granted under equity incentive plans	0	0
Unrecognized compensation expense related to non-vested stock options | $	$ 90,000
Recognition of unrecognized compensation expense, weighted-average period (in years)	8 months 1 day
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercisable period	7 years
2006 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding under equity incentive plans	810,000
Common stock available for future issuance	0
2015 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding under equity incentive plans	265,000
Common stock available for future issuance	1,080,000