CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets:
Allowance for doubtful accounts on trade accounts receivable	$ 18,967	$ 16,956
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares issued	1,015	1,015
Common stock, shares outstanding	1,015	1,015