Condensed Consolidated Balance Sheets (Parenthetical) (USD $)
In Thousands, except Share data, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Current assets:    
Allowance for doubtful accounts $ 27,125 $ 25,469
Accumulated depreciation on property, plant and equipment $ 813,562 $ 836,981
Shareholders’ equity:    
Common shares, par value (in dollars per share) $ 1.25 $ 1.25
Common shares, shares authorized 305,000,000 305,000,000
Common shares, shares issued 176,793,000 176,793,000
Treasury shares, shares 43,136,000 42,444,000