Consolidated Statements of Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Supplemental information:
(b) Operating expenses – related party	$ 9,910	$ 8,906
(c) General and administrative expenses – related party	2,858	2,599
(d) Interest and debt expense – related party	$ 1,566	$ 190