Discontinued Operations (Major Categories of Assets and Liabilities Reflected as Held for Sale) (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable		$ 432,791	$ 873,277	[1]
Total current assets held for sale		52,416	376,130	[1]
Property, plant and equipment, net		10,168,750	13,331,047	[1]
Other		293,409	62,582	[1]
Total non-current assets held for sale	[1]		50,960
Total current liabilities associated with assets held for sale		10,059	151,548	[1]
Deferred income taxes payable		306,379	1,193,864	[1]
Deferred credits and other liabilities		428,221	441,048	[1]
Total non-current liabilities associated with assets held for sale	[1]		8,310
UK Refining And Marketing Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash		20,738	200,512
Accounts receivable		12,067	97,568
Inventories		313	42,161
Other		19,298	35,889
Total current assets held for sale		52,416	376,130
Property, plant and equipment, net			50,947
Other			13
Total non-current assets held for sale			50,960
Accounts payable		2,895	59,023
Other accrued taxes payable		428	40,653
Accrued compensation and severance		3,715	30,872
Refinery decommissioning cost		3,021	21,000
Total current liabilities associated with assets held for sale		$ 10,059	151,548
Deferred income taxes payable			3,873
Deferred credits and other liabilities			4,437
Total non-current liabilities associated with assets held for sale			$ 8,310

[1] Reclassified to conform to current presentation.