CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total	Murphy Shareholders' Equity	Cumulative Preferred Stock	Common Stock	Capital In Excess Of Par Value	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2018				$ 195,077	$ 979,642	$ 5,513,529	$ 116,768	$ (609,787)	$ (1,249,162)	$ 368,343
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, including income tax benefits				6	(123)
Restricted stock transactions and other					(38,732)
Share-based compensation					17,676
Adjustments to acquisition valuation					(24,519)
Net (loss) income attributable to noncontrolling interest	$ 132,454					132,454				63,557
Cash dividends						(85,503)
Foreign currency translation (loss) gain, net of income taxes	54,055							54,055
Retirement and postretirement benefit plans, net of income taxes								5,516
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	1,171							1,171
Purchase of treasury shares									(299,924)
Awarded restricted stock, net of forfeitures									31,869
Acquisition closing adjustments										(4,592)
Distributions to noncontrolling interest owners										(68,776)
Balance at end of period at Jun. 30, 2019	5,098,545	$ 4,740,013	$ 0	195,083	933,944	5,677,248		(549,045)	(1,517,217)	358,532
Balance at beginning of period at Mar. 31, 2019				195,083	924,904	5,627,081		(580,999)	(1,217,293)	377,901
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation					9,040
Net (loss) income attributable to noncontrolling interest	92,272					92,272				30,970
Cash dividends						(42,105)
Foreign currency translation (loss) gain, net of income taxes	28,606							28,606
Retirement and postretirement benefit plans, net of income taxes								2,762
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	586							586
Purchase of treasury shares									(299,924)
Distributions to noncontrolling interest owners										(50,339)
Balance at end of period at Jun. 30, 2019	5,098,545	4,740,013	0	195,083	933,944	5,677,248		(549,045)	(1,517,217)	358,532
Balance at beginning of period at Dec. 31, 2019	5,804,611			195,089	949,445	6,614,304		(574,161)	(1,717,217)	337,151
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, including income tax benefits				12	(156)
Restricted stock transactions and other					(33,240)
Share-based compensation					15,380
Net (loss) income attributable to noncontrolling interest	(733,288)					(733,288)				(99,814)
Cash dividends						(57,590)
Foreign currency translation (loss) gain, net of income taxes	(67,843)							(67,843)
Retirement and postretirement benefit plans, net of income taxes								(48,945)
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	608							608
Awarded restricted stock, net of forfeitures									26,147
Distributions to noncontrolling interest owners										(32,400)
Balance at end of period at Jun. 30, 2020	4,773,482	4,568,545	0	195,101	931,429	5,823,426		(690,341)	(1,691,070)	204,937
Balance at beginning of period at Mar. 31, 2020				195,101	924,930	6,159,808		(701,984)	(1,691,706)	212,154
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock transactions and other					(636)
Share-based compensation					7,135
Net (loss) income attributable to noncontrolling interest	(317,184)					(317,184)				(7,216)
Cash dividends						(19,198)
Foreign currency translation (loss) gain, net of income taxes	50,568							50,568
Retirement and postretirement benefit plans, net of income taxes								(39,234)
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	309							309
Awarded restricted stock, net of forfeitures									636
Distributions to noncontrolling interest owners										(1)
Balance at end of period at Jun. 30, 2020	$ 4,773,482	$ 4,568,545	$ 0	$ 195,101	$ 931,429	$ 5,823,426		$ (690,341)	$ (1,691,070)	$ 204,937