CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Pool revenues, received from companies accounted for by the equity method	$ 30,224	$ 20,514	$ 98,115	$ 49,639