CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current Assets:
Allowance for doubtful accounts on trade accounts receivable	$ 49,068	$ 19,280
Common stock par value (in dollars per share)	$ 86.08
Class A common stock
Current Assets:
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,600,000,000	1,600,000,000
Common stock, shares issued	286,125,660	284,603,818
Common stock, shares outstanding	286,125,660	284,603,818
Class B common stock
Current Assets:
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	238,435,208	238,435,208
Common stock, shares outstanding	238,435,208	238,435,208