CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Allowance for Doubtful Accounts Receivable	$ 28,469	$ 34,479
Stockholders' Equity
Preferred stock, par value per share	$ 100	$ 100
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 1.00	$ 1.00
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	257,822,352	256,992,261
Treasury Stock, shares	112,905,810	102,168,868