Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Narrative (Details)

v3.2.0.727
Shareholders' Equity - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended 97 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Nov. 30, 2014
Oct. 31, 2011
Mar. 31, 2007
Capital Unit [Line Items]                
Shares authorized for repurchase               2,500,000
Shares authorized for additional repurchase           10,000,000 5,000,000  
Shares repurchased, shares 1,076,401   1,480,242   8,076,394      
Shares repurchased, value $ 3,848   $ 5,437   $ 21,061      
Options forfeited 9,928   65,640          
Unrecognized compensation cost for stock based compensation $ 14,192   $ 14,192   14,192      
Unrecognized compensation cost for stock based compensation, period of recognition     2 years 2 months 9 days          
Purchase of shares 197,070   686,654          
Intrinsic value of options exercised $ 536   $ 1,832          
Share-based compensation 2,424 $ 2,083 5,684 $ 4,010        
Grands in 2015 [Member]                
Capital Unit [Line Items]                
Unrecognized compensation cost for stock based compensation 3,556   $ 3,556   3,556      
Unrecognized compensation cost for stock based compensation, period of recognition     3 years 15 days          
Restricted shares                
Capital Unit [Line Items]                
Unrecognized compensation cost for stock based compensation 4,035   $ 4,035   $ 4,035      
Unrecognized compensation cost for stock based compensation, period of recognition     3 years 6 months 11 days          
Share-based compensation 963   $ 2,630          
Restricted shares | Grands in 2015 [Member]                
Capital Unit [Line Items]                
Unrecognized compensation cost for stock based compensation, period of recognition     3 years 6 months 4 days          
Options                
Capital Unit [Line Items]                
Share-based compensation $ 1,461   $ 3,054