Discontinued Operations (Narrative) (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended	0 Months Ended
	Sep. 30, 2013		Sep. 30, 2014 Milford Haven, Wales Refinery [Member]	Sep. 30, 2013 United Kingdon Upstream Operations [Member]	Oct. 01, 2014 Subsequent Event [Member]	Aug. 30, 2013 Murphy USA Inc [Member] item	Aug. 30, 2013 Murphy USA Inc [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales proceeds	$ 282,202,000	[1]			$ 232,700,000
Common stock outstanding							100.00%
Number of production facilities sold						2
After tax gain on sale of oil and natural gas production			$ 98,700,000	$ 216,200,000

[1] Reclassified to conform to current presentation - See Note D.