Shareholders' Equity - Preferred Stock, Cash Dividends and Stock Repurchase Program (Details) $ / shares in Units, $ in Thousands					3 Months Ended								12 Months Ended			24 Months Ended
	Feb. 28, 2017 $ / shares	Jan. 25, 2017 $ / shares	Jun. 04, 2015 $ / shares shares	Dec. 24, 2014 shares	Dec. 31, 2016 $ / shares shares	Sep. 30, 2016 $ / shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Dec. 31, 2015 USD ($) $ / shares shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares	Dec. 31, 2016 USD ($) series $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares shares	Jul. 22, 2016 USD ($)
Stock line items
Conversion price (in dollars per share) | $ / shares			$ 3.25
Cash dividend declared (in dollars per share) | $ / shares					$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.05	$ 0.24	$ 0.23	$ 0.08
Cash dividend paid on common stock (in dollars per share) | $ / shares	$ 0.06												$ 0.24	$ 0.23
Shares repurchased and cancelled | shares													226,170			281,598
Cost of shares repurchased and cancelled | $													$ 1,600			$ 2,100
Price per share of shares repurchased and cancelled | $ / shares													$ 7.23			$ 7.28
Minimum
Stock line items
Number of series of preferred stock | series													1
Maximum
Stock line items
Preferred stock, shares authorized | shares					5,000,000								5,000,000			5,000,000
Repurchase of shares, dollar amount authorized | $																	$ 5,000
Subsequent Event
Stock line items
Cash dividend paid on common stock (in dollars per share) | $ / shares		$ 0.06
Series C preferred stock
Stock line items
Conversion of Series C preferred stock (in shares) | shares			348,697	840,841
Preferred stock conversion ratio			1
Preferred stock, shares issued | shares									0					0
Preferred stock, shares outstanding | shares									0					0
Value of contingent beneficial conversion feature to be recognized upon conversion | $									$ 70					$ 70	$ 168