Discontinued Operations (Major Categories of Assets and Liabilities Reflected as Held for Sale) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable	$ 542,417	$ 873,277	[1]
Total current assets held for sale	279,799	376,130	[1]
Property, plant and equipment, net	12,577,749	13,331,047	[1]
Other	72,768	62,582	[1]
Total non-current assets held for sale	14	50,960	[1]
Total current liabilities associated with assets held for sale	56,334	151,548	[1]
Deferred income taxes payable	937,745	1,193,864	[1]
Deferred credits and other liabilities	429,485	441,048	[1]
Total non-current liabilities associated with assets held for sale	551	8,310	[1]
UK Refining And Marketing Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	111,286	200,512
Accounts receivable	146,651	97,568
Inventories	325	42,161
Other	21,537	35,889
Total current assets held for sale	279,799	376,130
Property, plant and equipment, net		50,947
Other	14	13
Total non-current assets held for sale	14	50,960
Accounts payable	7,897	59,023
Other accrued taxes payable	31,519	40,653
Accrued compensation and severance	16,320	30,872
Refinery decommissioning cost	598	21,000
Total current liabilities associated with assets held for sale	56,334	151,548
Deferred income taxes payable		3,873
Deferred credits and other liabilities	551	4,437
Total non-current liabilities associated with assets held for sale	$ 551	$ 8,310

[1] Reclassified to conform to current presentation.