Condensed Consolidated Statements of Operations - Entity [Domain] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues	$ 3,550,664	$ 5,301,709	$ 6,545,800	$ 10,048,152
Costs and expenses:
Cost of sales, excluding depreciation	3,026,975	4,943,238	5,556,015	9,090,922
Operating expenses, excluding depreciation	192,150	209,781	425,527	478,680
General and administrative expenses	35,783	32,095	68,313	68,719
(Gain) loss on sale of assets	(632)	6	(991)	(180)
Depreciation and amortization expense	47,015	34,516	93,274	67,731
Total cost and expenses	3,301,291	5,219,636	6,142,138	9,705,872
Income from operations	249,373	82,073	403,662	342,280
Other income (expense)
Change in fair value of catalyst leases	1,949	(2,338)	3,988	(4,339)
Interest expense, net	(22,955)	(26,217)	(44,027)	(51,673)
Net income	$ 228,367	$ 53,518	$ 363,623	$ 286,268