Stockholders' Equity (Details)		12 Months Ended
	Aug. 06, 2013 shares	Dec. 31, 2017 USD ($) $ / shares shares	Sep. 05, 2017 USD ($) SubscriptionRight $ / shares	Dec. 31, 2016 USD ($) shares	Aug. 29, 2011 shares
Equity Class Of Treasury Stock [Line Items]
Number of shares authorized and available for repurchase (in shares)		540,000			100,000
Treasury stock, shares (in shares)		81,584		81,584
Value of repurchased common stock | $		$ 580,000		$ 580,000
Distribution charge of common stock transferable subscription rights | $			$ 0
Number of transferable subscription rights for each common stock owned | SubscriptionRight			3
Percentage of share of common stock holder is entitled to purchase by each subscription right			0.25%
Common stock subscription price | $ / shares			$ 5.50
Gross proceeds from issuance of common stock | $		11,036,000
Common stock issuance cost | $		$ 242,000
Common stock subscription shares		2,897,171
Expected dividend rate		0.00%
Fair value of subscription rights at time of original issuance | $		$ 10,000
Total warrants distributed (in shares)	12,981,025
Dividend declaration date		Aug. 06, 2013
Dividend date of record		Jul. 29, 2013
Number of warrants received for each share of common stock (in shares)		5
Number of warrants that entitle holder to purchase one share of common stock (in shares)		25
Number of common shares callable by warrants (in shares)		1
Warrant exercise price (in dollars per share) | $ / shares		$ 7.50
Minimum volume weighted average price per share (in dollars per share) | $ / shares		$ 15.00
Common Stock [Member]
Equity Class Of Treasury Stock [Line Items]
Number of shares issued to existing shareholders		2,006,598
Common Stock [Member] | Maximum [Member]
Equity Class Of Treasury Stock [Line Items]
Number of shares issued to existing shareholders		2,006,598
Over-subscription Right [Member]
Equity Class Of Treasury Stock [Line Items]
Common stock subscription price | $ / shares		$ 5.50
Common stock shares issued pro rata basis		686,439