CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trade accounts receivables, allowance for doubtful accounts	$ 3,711	$ 4,460
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	106,040,000	105,616,000
Common stock, shares outstanding	106,040,000	105,616,000