XML 17 R5.htm IDEA: XBRL DOCUMENT v3.8.0.1
Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Assets:    
Allowance for doubtful accounts, current $ 15,288 $ 13,847
Operating property and equipment, accumulated depreciation 1,210,379 1,192,377
Finite-Lived intangible assets, accumulated amortization $ 58,760 $ 57,420
Shareholders’ equity:    
Common stock, par value (in dollars per share) $ 0.50 $ 0.50
Common stock, shares authorized (in shares) 400,000,000 400,000,000
Common stock, shares outstanding (in shares) 53,094,898 52,955,314
Preferred stock, par value (in dollars per share) $ 0 $ 0
Preferred stock, shares authorized (in shares) 3,800,917 3,800,917
Preferred stock, shares outstanding (in shares) 0 0