Incentive Plans (Changes in Stock Options Outstanding) (Details) - $ / shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of Shares
Exercised	[1]	(15,575)	(119,994)	(303,685)
Outstanding at end of year		5,443,288
Exercisable at end of year		3,542,352
Stock Options [Member]
Number of Shares
Outstanding at beginning of year		5,602,250	6,006,585	5,907,359
Granted at FMV		991,000	772,900	1,320,176
Exercised		(32,349)	(862,407)	(1,335,355)
Forfeited		(1,117,613)	(314,828)	(228,576)
Surrendered in connection with separation of Murphy USA Inc.				(272,936)
Murphy USA Inc. spin-off adjustment				615,917
Outstanding at end of year		5,443,288	5,602,250	6,006,585
Exercisable at end of year		3,542,352	3,030,105	2,435,322	2,474,636
Average Exercise Price
Outstanding at beginning of year		$ 57.95	$ 56.80	$ 55.17
Granted at FMV		49.67	55.82	55.26
Exercised		40.80	49.27	45.84
Forfeited		31.99	54.53	58.01
Surrendered in connection with separation of Murphy USA Inc.				55.99
Murphy USA Inc. spin-off adjustment				52.09
Outstanding at end of year		52.93	57.95	56.80
Exercisable at end of year		$ 52.26	$ 53.10	$ 51.79	$ 54.43

[1] Shares issued upon exercise of stock options and award of restricted stock are less than the amount reflected in Note J due to withholdings for statutory income taxes owed upon issuance of shares.