Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation (Narrative) (Details)

v3.6.0.2
Share-Based Compensation (Narrative) (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash-settleable restricted stock unit awards $ 8,919 $ 10,128  
Payments to settle vested liability share-based awards $ 10,300 $ 3,925 $ 2,052
Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of years company issued no stock options 3 years    
Issued, shares 0    
Vested, shares 0    
Forfeited, shares 0    
Exercised, shares 0    
Expired, shares 0    
Outstanding, shares 15,000 15,000 30,000
Exercisable, shares 15,000 15,000 30,000
Outstanding, end of year, weighted average exercise price per option $ 14.37 $ 14.37 $ 14.04
Share-based payment award outstanding aggregate intrinsic value $ 0 $ 0 $ 0
Outstanding options weighted-average remaining contract life per unit 3 months 18 days 1 year 3 months 18 days 1 year 3 months 18 days
RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average period over which expense is expected to be recognized 1 year 7 months 6 days    
Granted 684,000 559,556 333,468
Granted, grant date fair value per share $ 12.63 $ 8.98 $ 9.67
Fair value of shares vested   $ 5,425 $ 4,338
Vested in period 630,000    
Cash-settleable RSU awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average period over which expense is expected to be recognized 2 years    
Unvested RSUs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average period over which expense is expected to be recognized 2 years    
Non-Market Based Cash-settleable RSU Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payments to settle vested liability share-based awards $ 493 $ 545  
Vested in period 45,282 72,108  
Market-based Cash-settleable RSU Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Payments to settle vested liability share-based awards $ 9,807 $ 3,319  
Vested in period 281,792 853,673  
2011 Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares available for grant 2,270,448    
Vesting in 2017 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash-settleable restricted stock unit awards $ 8,662    
Vesting Minimum [Member] | Cash-settleable RSU awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement vesting rights, percentage 0.00%    
Vesting Minimum [Member] | Market-based Cash-settleable RSU Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement vesting rights, percentage   150.00%  
Vesting Maximum [Member] | Cash-settleable RSU awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement vesting rights, percentage 200.00%    
Vesting Maximum [Member] | Non-Market Based Cash-settleable RSU Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement vesting rights, percentage 200.00%    
Vesting Maximum [Member] | Market-based Cash-settleable RSU Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement vesting rights, percentage   200.00%