Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Narrative (Details)

v3.5.0.2
Shareholders' Equity - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended 115 Months Ended
Sep. 30, 2016
Sep. 30, 2016
Sep. 30, 2016
Nov. 07, 2016
Oct. 31, 2016
Oct. 26, 2016
May 18, 2016
Dec. 31, 2015
Oct. 31, 2011
Mar. 31, 2007
Capital Unit [Line Items]                    
Shares authorized for repurchase (in shares) (up to)                   2,500,000
Shares authorized for additional repurchase (in shares)                 5,000,000  
Repurchase and retirement of common stock (in shares) 1,597,126 4,693,037 16,962,604              
Shares repurchased, value $ 3,800 $ 11,515 $ 43,496              
Shares available for purchase (in shares) 537,396 537,396 537,396              
Shares surrendered for tax withholdings (in shares)   901,691                
Preferred stock, shares authorized (in shares) 50,000,000 50,000,000 50,000,000       50,000,000 25,000,000    
Common stock, shares authorized (in shares) 1,000,000,000 1,000,000,000 1,000,000,000       1,000,000,000 800,000,000    
Options                    
Capital Unit [Line Items]                    
Options forfeited (in shares) 17,407 69,835                
Unrecognized compensation cost for stock based compensation $ 4,984 $ 4,984 $ 4,984              
Unrecognized compensation cost for stock based compensation, period of recognition   2 years 1 month 13 days                
Purchase of shares (in shares) 3,797,272 7,356,887                
Intrinsic value of options exercised $ 5,426 $ 10,210                
Options | Awards Granted in 2016                    
Capital Unit [Line Items]                    
Unrecognized compensation cost for stock based compensation 1,060 $ 1,060 1,060              
Unrecognized compensation cost for stock based compensation, period of recognition   2 years 8 months 2 days                
Restricted shares                    
Capital Unit [Line Items]                    
Unrecognized compensation cost for stock based compensation 5,006 $ 5,006 5,006              
Unrecognized compensation cost for stock based compensation, period of recognition   2 years 8 months 18 days                
Restricted stock forfeited (in shares)   10,000                
Restricted shares | Employees                    
Capital Unit [Line Items]                    
Non-cash compensation expense 1,286 $ 3,964                
Restricted shares | Consultants and Independent Financial Advisors                    
Capital Unit [Line Items]                    
Non-cash compensation expense 14 32                
Restricted shares | Awards Granted in 2016                    
Capital Unit [Line Items]                    
Unrecognized compensation cost for stock based compensation $ 2,358 $ 2,358 $ 2,358              
Unrecognized compensation cost for stock based compensation, period of recognition   3 years 3 months                
Options, Warrants, and Other                    
Capital Unit [Line Items]                    
Shares surrendered for tax withholdings (in shares) 1,588,988 2,865,263                
Series A Preferred Stock                    
Capital Unit [Line Items]                    
Preferred stock, shares authorized (in shares) 17,290,000 17,290,000 17,290,000         17,290,000    
At the market shares sold (in shares) 789,468 1,161,895                
Proceeds from issuance of public offering $ 19,266 $ 28,303                
Offering expenses 422 682                
Dividends paid $ 7,780 $ 22,514                
Dividends paid per share on monthly basis (in USD per share)   $ 0.1667                
Subsequent Event                    
Capital Unit [Line Items]                    
Shares authorized for repurchase (in shares) (up to)       10,000,000 10,000,000          
Number of securities purchased by conversion of warrant (in shares)           10,699,999