Statements of Consolidated Shareholders' Equity (USD $)
In Thousands, except Share data, unless otherwise specified
Total
Common shares
Additional paid-in capital
Common shares subscribed, unissued
Retained earnings
Accumulated other comprehensive income (loss), net of tax
Common shares held in treasury
Common shares subscription receivable
Balance at the beginning of the year at Dec. 31, 2011 $ (6,344)         $ (6,344)    
Balance at beginning of year, value at Dec. 31, 2011   (21,457) (1,721) 0 (188,613)   104,721 0
Common shares, at beginning of year at Dec. 31, 2011   21,457,000            
Share subscriptions, beginning balance, shares at Dec. 31, 2011       0       0
Balance at beginning of year, shares at Dec. 31, 2011             7,611,000  
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Shares sold to employees, value     1,742       4,390  
Options exercised, value     (2,100)       (5,197)  
Subscription shares, issued, value     428       1,078  
Stock-based compensation     1,640          
Common shares, subscribed, value       (12,563)       (9,732)
Common shares, subscribed, shares       (638,000)       (638,000)
Common shares, issued, value       (1,508)       (517)
Common shares, issued, shares       (77,000)       (77,000)
Cancellations, value       0       0
Cancellations, shares       0       0
Net income 24,595       24,595      
Dividends         (2,556)      
Currency translation adjustments           561    
Net gain (loss) on interest rate contracts 77         77    
Defined benefit pension plans 1,409         (1,409)    
Shares purchased, value             (18,103)  
Shares purchased, shares             892,000  
Shares sold to employees, shares             (327,000)  
Options exercised, shares             (368,000)  
Subscription shares, issued, shares             (77,000)  
Balance at the end of the year at Dec. 31, 2012 (7,115)         (7,115)    
Balance at ending of year, value at Dec. 31, 2012 (118,106) (21,457) (3,431) (11,055) (210,652)   112,159 (9,215)
Common shares, at end of year at Dec. 31, 2012 21,456,880 21,457,000            
Share subscriptions, ending balance, shares at Dec. 31, 2012       (561,000)       (561,000)
Balance at ending of year, shares at Dec. 31, 2012 13,726,000           7,731,000  
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Shares sold to employees, value     2,745       3,853  
Options exercised, value     (2,273)       (4,776)  
Subscription shares, issued, value     98       383  
Stock-based compensation     1,007          
Common shares, subscribed, value       0       0
Common shares, subscribed, shares       0       0
Common shares, issued, value       (409)       (1,728)
Common shares, issued, shares       (21,000)       (21,000)
Cancellations, value       (179)       (145)
Cancellations, shares       (9,000)       (9,000)
Net income 22,853       22,853      
Dividends         (2,530)      
Currency translation adjustments           (1,864)    
Net gain (loss) on interest rate contracts 0         0    
Defined benefit pension plans (4,586)         4,586    
Shares purchased, value             (21,887)  
Shares purchased, shares 931,078           931,000  
Shares sold to employees, shares (299,330)           (299,000)  
Options exercised, shares             (319,000)  
Subscription shares, issued, shares             (26,000)  
Balance at the end of the year at Dec. 31, 2013 (4,393)         (4,393)    
Balance at ending of year, value at Dec. 31, 2013 (131,138) (21,457) (5,008) (10,467) (230,975)   125,034 (7,342)
Common shares, at end of year at Dec. 31, 2013 21,456,880 21,457,000            
Share subscriptions, ending balance, shares at Dec. 31, 2013       (531,000)       (531,000)
Balance at ending of year, shares at Dec. 31, 2013 13,439,000 21,456,880         8,018,000  
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Shares sold to employees, value     3,417       3,822  
Options exercised, value     (273)       (1,861)  
Subscription shares, issued, value     184       794  
Stock-based compensation     1,125          
Common shares, subscribed, value (12,563)     0       0
Common shares, subscribed, shares (637,714)     0       0
Common shares, issued, value       (758)       (1,543)
Common shares, issued, shares       (39,000)       (39,000)
Cancellations, value       (328)       (199)
Cancellations, shares       (16,000)       (16,000)
Net income 23,169       23,169      
Dividends         (2,674)      
Currency translation adjustments           (2,798)    
Net gain (loss) on interest rate contracts 0         0    
Defined benefit pension plans 4,332         (4,332)    
Shares purchased, value             (19,598)  
Shares purchased, shares 727,436           727,000  
Shares sold to employees, shares (287,536)           (287,000)  
Options exercised, shares (74,715)           (116,000)  
Subscription shares, issued, shares             (50,000)  
Balance at the end of the year at Dec. 31, 2014 (11,523)         (11,523)    
Balance at ending of year, value at Dec. 31, 2014 $ (136,491) $ (21,457) $ (9,461) $ (9,381) $ (251,470)   $ 138,155 $ (5,600)
Common shares, at end of year at Dec. 31, 2014 21,456,880 21,457,000            
Share subscriptions, ending balance, shares at Dec. 31, 2014       (476,000)       (476,000)
Balance at ending of year, shares at Dec. 31, 2014 13,165,000 21,456,880         8,292,000