Shareholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($) shares	Mar. 31, 2013	Sep. 30, 2011	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 $ / shares shares	Nov. 30, 2010	Mar. 31, 2002 $ / shares shares
Class of Stock [Line Items]
Common stock, shares authorized				150,000,000	150,000,000
Common stock, par value | $ / shares				$ 0.01	$ 0.01
Common stock, shares issued				12,256,980	12,257,000
Common stock, shares outstanding				10,844,113	10,844,000
Preferred stock, shares authorized				1,000,000	1,000,000
Preferred stock, par value | $ / shares				$ 0.01	$ 0.01
Preferred stock, shares issued				0
Preferred stock, shares outstanding				0
Preferred stock, redemption date				Jun. 30, 2017
Dividends declared, share, preferred stock purchase right for outstanding common stock							1
Exercise Price | $ / shares				$ 0.01
Minimum ownership percentage for change				5.00%
Period for ownership change				3 years
Right plan expiration date		Jul. 03, 2013	Mar. 12, 2012
Right plan extended expiration date		Jul. 03, 2016	Jul. 03, 2013
Conversion Threshold, 15% [Member]
Class of Stock [Line Items]
Preferred stock, conversion trigger, percentage ownership change							15.00%
Conversion Threshold, Greater than 15% and Less than 50% [Member]
Class of Stock [Line Items]
Preferred stock, conversion trigger, percentage ownership change							50.00%
Conversion Threshold, Revised, 4.99% [Member]
Class of Stock [Line Items]
Preferred stock, conversion trigger, percentage ownership change						4.99%
Series B Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued				0	130
Preferred stock, shares outstanding				0	130
Each share of preferred stock converted into common stock	2.78
Preferred shares converted into common stock, shares	361
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares outstanding				0	550
Payment for redemption of preferred stock | $	$ 10
Amount recorded in excess of carrying value over redemption value | $				$ 459
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, conversion amount, per one thousandth of a share | $ / shares							$ 30