Discontinued Operations and Assets Held for Sale (Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended
	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sales of property, plant and equipment			$ 1,155,144,000	$ 423,911,000	$ 1,467,046,000
Impairment of assets			$ 95,088,000	2,493,156,000	51,314,000
Gain on disposal				$ (4,990,000)	101,684,000
UK Refining And Marketing Operations [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sales of property, plant and equipment	$ 211,965,000	$ 5,500,000
Impairment of assets					269,200,000
Effect of LIFO Inventory Liquidation on Income					209,600,000
Gain on disposal					$ 101,700,000