CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Balance Sheet Parenthetical Disclosures
Accounts receivable, allowance (in dollars)	$ 6,899	$ 5,127
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares issued (in shares)	491,108,584	477,496,499
Common stock, shares outstanding (in shares)	491,108,584	477,496,499