Summary of Significant Accounting Policies - Calculation of Basic and Diluted (Loss) Income Per Common Share and Common Share Equivalents (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic net (loss) income per common share
Net (loss) income	$ 1,167	$ (1,410)	$ (376)	$ (1,441)	$ 9,614	$ 248	$ (2,268)	$ (1,643)	$ (2,060)	$ 5,951	$ (1,496)
Less: Preferred stock dividends									(14)	(28)	(28)
Net (loss) income available to common stockholders									$ (1,615)	$ 5,923	$ (1,524)
Basic weighted average common shares outstanding									10,824	10,795	10,774
Basic net (loss) income per common share	$ 0.11	$ (0.13)	$ 0.01	$ (0.13)	$ 0.89	$ 0.02	$ (0.21)	$ (0.15)	$ (0.15)	$ 0.55	$ (0.14)
Diluted net (loss) income per common share
Net (loss) income applicable to common stock									$ (1,615)	$ 5,923	$ (1,524)
Add: Preferred stock dividends									14	28	28
Net (loss) income applicable to dilutive common stock									$ (1,615)	$ 5,951	$ (1,524)
Basic weighted average common shares outstanding									10,824	10,795	10,774
Effect of dilutive securities
Dilutive preferred share conversions										83
Dilutive stock awards										13
Weighted average number of diluted shares outstanding adjustment										96
Diluted weighted average number of common shares outstanding									10,824	10,891	10,774
Diluted net (loss) income per common share	$ 0.11	$ (0.13)	$ (0.03)	$ (0.13)	$ 0.88	$ 0.02	$ (0.21)	$ (0.15)	$ (0.15)	$ 0.55	$ (0.14)
Series C Preferred Stock [Member]
Basic net (loss) income per common share
Add: Excess of carrying value of Series C Preferred Stock over redemption value									$ 459