CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance, in dollars	$ 5,127	$ 4,425
Common stock, par value, in dollars per share	$ 1.00	$ 1.00
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	477,496,499	469,435,678
Common stock, shares outstanding	477,496,499	469,435,678