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	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2019				$ 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 income (loss)	$ (733,288)					(733,288)			(99,814)
Cash dividends						(57,590)
Foreign currency translation gain (loss), 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 income (loss)	(317,184)					(317,184)			(7,216)
Cash dividends						(19,198)
Foreign currency translation gain (loss), 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
Balance at beginning of period at Dec. 31, 2020	4,394,147			195,101	941,692	5,369,538	(601,333)	(1,690,661)	179,810
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, including income tax benefits					(626)			525
Restricted stock transactions and other					(38,347)
Share-based compensation					12,462
Net income (loss)	(350,520)					(350,520)			56,656
Cash dividends						(38,590)
Foreign currency translation gain (loss), net of income taxes	37,842						37,842
Retirement and postretirement benefit plans, net of income taxes							8,282
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	1,690						1,690
Awarded restricted stock, net of forfeitures								33,545
Distributions to noncontrolling interest owners									(75,238)
Balance at end of period at Jun. 30, 2021	4,041,828	3,880,600	0	195,101	915,181	4,980,428	(553,519)	(1,656,591)	161,228
Balance at beginning of period at Mar. 31, 2021				195,101	914,303	5,062,813	(575,610)	(1,661,416)	164,418
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, including income tax benefits					(587)			486
Restricted stock transactions and other					(5,347)
Share-based compensation					6,812
Net income (loss)	(63,082)					(63,082)			36,042
Cash dividends						(19,303)
Foreign currency translation gain (loss), net of income taxes	17,945						17,945
Retirement and postretirement benefit plans, net of income taxes							4,146
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes	0
Awarded restricted stock, net of forfeitures								4,339
Distributions to noncontrolling interest owners									(39,232)
Balance at end of period at Jun. 30, 2021	$ 4,041,828	$ 3,880,600	$ 0	$ 195,101	$ 915,181	$ 4,980,428	$ (553,519)	$ (1,656,591)	$ 161,228