SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Oil and Gas Reserve Information (Detail) MBoe in Thousands	12 Months Ended
	Dec. 31, 2017 MBoe MMcf MBbls	Dec. 31, 2016 MBoe MMcf MBbls	Dec. 31, 2015 MBoe MMcf MBbls	Dec. 31, 2014 MBoe MMcf MBbls
Reserve Quantities [Line Items]
Proved developed reserves	1,023,663	1,173,635	1,331,397	1,651,291
Proved undeveloped reserves	151,323	137,616	232,336	744,979
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	1,311,251	1,563,733	2,396,270
Extensions, discoveries and other additions	229,977	103,204	117,405
Purchases of minerals in-place	2,285	1,580	6,860
Revisions of previous estimates	10,394	(159,341)	(365,135)
Production	(166,923)	(190,942)	(206,840)
Sales of minerals in-place	(211,998)	(6,983)	(384,827)
Ending balance	1,174,986	1,311,251	1,563,733
United States
Reserve Quantities [Line Items]
Proved developed reserves	699,786	656,087	726,424	897,422
Proved undeveloped reserves	111,001	76,950	120,210	336,670
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	733,037	846,634	1,234,092
Extensions, discoveries and other additions	145,322	56,458	26,488
Purchases of minerals in-place	991	24	0
Revisions of previous estimates	12,903	(87,954)	(322,123)
Production	(75,151)	(81,994)	(91,591)
Sales of minerals in-place	(6,315)	(131)	(232)
Ending balance	810,787	733,037	846,634
Canada
Reserve Quantities [Line Items]
Proved developed reserves	0	157,662	209,647	258,848
Proved undeveloped reserves	0	17,931	70,300	155,028
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	175,593	279,947	413,876
Extensions, discoveries and other additions	24,115	9,166	26,226
Purchases of minerals in-place	1,294	0	6,860
Revisions of previous estimates	16,136	(84,984)	(87,081)
Production	(11,455)	(21,684)	(24,706)
Sales of minerals in-place	(205,683)	(6,852)	(55,228)
Ending balance	0	175,593	279,947
Egypt
Reserve Quantities [Line Items]
Proved developed reserves	215,364	252,630	275,033	236,256
Proved undeveloped reserves	24,112	27,336	26,929	43,446
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	279,966	301,962	279,702
Extensions, discoveries and other additions	40,731	23,674	40,464
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	(21,936)	16,599	37,825
Production	(59,285)	(62,269)	(56,029)
Sales of minerals in-place	0	0	0
Ending balance	239,476	279,966	301,962
Australia
Reserve Quantities [Line Items]
Proved developed reserves	0	0	0	136,707
Proved undeveloped reserves	0	0	0	186,534
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	0	0	323,241
Extensions, discoveries and other additions	0	0	0
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	0	0	12,549
Production	0	0	(8,503)
Sales of minerals in-place	0	0	(327,287)
Ending balance	0	0	0
North Sea
Reserve Quantities [Line Items]
Proved developed reserves	108,513	107,256	120,293	122,058
Proved undeveloped reserves	16,210	15,399	14,897	23,301
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	122,655	135,190	145,359
Extensions, discoveries and other additions	19,809	13,906	24,227
Purchases of minerals in-place	0	1,556	0
Revisions of previous estimates	3,291	(3,002)	(6,305)
Production	(21,032)	(24,995)	(26,011)
Sales of minerals in-place	0	0	(2,080)
Ending balance	124,723	122,655	135,190
Crude Oil and Condensate
Reserve Quantities [Line Items]
Proved developed reserves	521,445	582,317	665,063	784,770
Proved undeveloped reserves	62,115	59,965	127,996	289,499
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	642,282	793,059	1,074,269
Extensions, discoveries and other additions	105,579	40,351	59,556
Purchases of minerals in-place	421	459	1,763
Revisions of previous estimates	(675)	(88,714)	(165,609)
Production	(89,156)	(100,744)	(108,491)
Sales of minerals in-place	(74,891)	(2,129)	(68,429)
Ending balance	583,560	642,282	793,059
Crude Oil and Condensate | United States
Reserve Quantities [Line Items]
Proved developed reserves	304,279	300,900	348,797	444,440
Proved undeveloped reserves	31,904	21,088	60,505	170,125
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	321,988	409,302	614,565
Extensions, discoveries and other additions	48,391	9,614	13,903
Purchases of minerals in-place	46	21	0
Revisions of previous estimates	825	(58,882)	(173,907)
Production	(33,394)	(38,000)	(45,138)
Sales of minerals in-place	(1,673)	(67)	(121)
Ending balance	336,183	321,988	409,302
Crude Oil and Condensate | Canada
Reserve Quantities [Line Items]
Proved developed reserves	0	51,508	67,847	75,876
Proved undeveloped reserves	0	7,906	38,326	59,923
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	59,414	106,173	135,799
Extensions, discoveries and other additions	14,025	3,372	4,550
Purchases of minerals in-place	375	0	1,763
Revisions of previous estimates	1,829	(43,282)	(27,966)
Production	(2,425)	(4,787)	(5,755)
Sales of minerals in-place	(73,218)	(2,062)	(2,218)
Ending balance	0	59,414	106,173
Crude Oil and Condensate | Egypt
Reserve Quantities [Line Items]
Proved developed reserves	124,568	138,771	144,164	128,712
Proved undeveloped reserves	16,198	20,187	17,856	14,617
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	158,958	162,020	143,329
Extensions, discoveries and other additions	27,140	17,599	24,524
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	(9,839)	17,301	27,330
Production	(35,493)	(37,962)	(33,163)
Sales of minerals in-place	0	0	0
Ending balance	140,766	158,958	162,020
Crude Oil and Condensate | Australia
Reserve Quantities [Line Items]
Proved developed reserves	0	0	0	29,996
Proved undeveloped reserves	0	0	0	25,775
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	0	0	55,771
Extensions, discoveries and other additions	0	0	0
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	0	0	11,189
Production	0	0	(2,778)
Sales of minerals in-place	0	0	(64,182)
Ending balance	0	0	0
Crude Oil and Condensate | North Sea
Reserve Quantities [Line Items]
Proved developed reserves	92,598	91,138	104,255	105,746
Proved undeveloped reserves	14,013	10,784	11,309	19,059
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	101,922	115,564	124,805
Extensions, discoveries and other additions	16,023	9,766	16,579
Purchases of minerals in-place	0	438	0
Revisions of previous estimates	6,510	(3,851)	(2,255)
Production	(17,844)	(19,995)	(21,657)
Sales of minerals in-place	0	0	(1,908)
Ending balance	106,611	101,922	115,564
Natural Gas Liquids
Reserve Quantities [Line Items]
Proved developed reserves	173,715	171,883	168,786	204,628
Proved undeveloped reserves	29,951	20,561	30,151	77,579
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	192,444	198,937	282,207
Extensions, discoveries and other additions	36,495	11,872	8,074
Purchases of minerals in-place	405	7	976
Revisions of previous estimates	11,176	5,627	(69,178)
Production	(19,515)	(22,942)	(22,721)
Sales of minerals in-place	(17,339)	(1,057)	(421)
Ending balance	203,666	192,444	198,937
Natural Gas Liquids | United States
Reserve Quantities [Line Items]
Proved developed reserves	171,005	155,124	150,265	183,565
Proved undeveloped reserves	29,559	17,311	24,939	69,828
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	172,435	175,204	253,393
Extensions, discoveries and other additions	33,806	10,238	5,768
Purchases of minerals in-place	206	2	0
Revisions of previous estimates	12,982	6,824	(64,226)
Production	(17,766)	(19,824)	(19,684)
Sales of minerals in-place	(1,099)	(9)	(47)
Ending balance	200,564	172,435	175,204
Natural Gas Liquids | Canada
Reserve Quantities [Line Items]
Proved developed reserves	0	13,866	15,246	17,947
Proved undeveloped reserves	0	2,473	4,839	7,168
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	16,339	20,085	25,115
Extensions, discoveries and other additions	1,794	755	1,473
Purchases of minerals in-place	199	0	976
Revisions of previous estimates	(1,060)	(1,355)	(4,886)
Production	(1,032)	(2,098)	(2,236)
Sales of minerals in-place	(16,240)	(1,048)	(357)
Ending balance	0	16,339	20,085
Natural Gas Liquids | Egypt
Reserve Quantities [Line Items]
Proved developed reserves	685	1,266	1,491	1,346
Proved undeveloped reserves	39	131	78	212
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	1,397	1,569	1,558
Extensions, discoveries and other additions	50	208	144
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	(425)	17	255
Production	(298)	(397)	(388)
Sales of minerals in-place	0	0	0
Ending balance	724	1,397	1,569
Natural Gas Liquids | North Sea
Reserve Quantities [Line Items]
Proved developed reserves	2,025	1,627	1,784	1,770
Proved undeveloped reserves	353	646	295	371
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance	2,273	2,079	2,141
Extensions, discoveries and other additions	845	671	689
Purchases of minerals in-place	0	5	0
Revisions of previous estimates	(321)	141	(321)
Production	(419)	(623)	(413)
Sales of minerals in-place	0	0	(17)
Ending balance	2,378	2,273	2,079
Natural Gas
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	1,971,018	2,516,610	2,985,290	3,971,360
Proved undeveloped reserves | MMcf	355,544	342,538	445,132	2,267,400
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	2,859,148	3,430,422	6,238,760
Extensions, discoveries and other additions | MMcf	527,418	305,883	298,649
Purchases of minerals in-place | MMcf	8,753	6,684	24,727
Revisions of previous estimates | MMcf	(641)	(457,524)	(782,083)
Production | MMcf	(349,509)	(403,533)	(453,772)
Sales of minerals in-place | MMcf	(718,607)	(22,784)	(1,895,859)
Ending balance | MMcf	2,326,562	2,859,148	3,430,422
Natural Gas | United States
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	1,347,009	1,200,379	1,364,174	1,616,504
Proved undeveloped reserves | MMcf	297,226	231,304	208,594	580,299
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	1,431,683	1,572,768	2,196,803
Extensions, discoveries and other additions | MMcf	378,747	219,633	40,901
Purchases of minerals in-place | MMcf	4,434	7	0
Revisions of previous estimates | MMcf	(5,431)	(215,378)	(503,939)
Production | MMcf	(143,943)	(145,019)	(160,614)
Sales of minerals in-place | MMcf	(21,255)	(328)	(383)
Ending balance | MMcf	1,644,235	1,431,683	1,572,768
Natural Gas | Canada
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	0	553,724	759,321	990,145
Proved undeveloped reserves | MMcf	0	45,312	162,809	527,623
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	599,036	922,130	1,517,768
Extensions, discoveries and other additions | MMcf	49,780	30,234	121,216
Purchases of minerals in-place	4,319	0	24,727
Revisions of previous estimates	92,207	(242,080)	(325,375)
Production	(47,990)	(88,792)	(100,289)
Sales of minerals in-place	(697,352)	(22,456)	(315,917)
Ending balance | MMcf	0	599,036	922,130
Natural Gas | Egypt
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	540,667	675,559	776,263	637,187
Proved undeveloped reserves | MMcf	47,255	42,109	53,969	171,696
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	717,668	830,232	808,883
Extensions, discoveries and other additions | MMcf	81,245	35,202	94,777
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	(70,030)	(4,305)	61,442
Production	(140,961)	(143,461)	(134,870)
Sales of minerals in-place	0	0	0
Ending balance | MMcf	587,922	717,668	830,232
Natural Gas | Australia
Reserve Quantities [Line Items]
Proved developed reserves	0	0	0	640,265
Proved undeveloped reserves	0	0	0	964,554
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	0	0	1,604,819
Extensions, discoveries and other additions | MMcf	0	0	0
Purchases of minerals in-place	0	0	0
Revisions of previous estimates	0	0	8,162
Production	0	0	(34,352)
Sales of minerals in-place	0	0	(1,578,629)
Ending balance | MMcf	0	0	0
Natural Gas | North Sea
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	83,342	86,948	85,532	87,259
Proved undeveloped reserves | MMcf	11,063	23,813	19,760	23,228
Proved Developed and Undeveloped Reserves [Roll Forward]
Beginning balance | MMcf	110,761	105,292	110,487
Extensions, discoveries and other additions | MMcf	17,646	20,814	41,755
Purchases of minerals in-place	0	6,677	0
Revisions of previous estimates	(17,387)	4,239	(22,373)
Production	(16,615)	(26,261)	(23,647)
Sales of minerals in-place	0	0	(930)
Ending balance | MMcf	94,405	110,761	105,292
Noncontrolling Interest | Egypt
Proved Developed and Undeveloped Reserves [Roll Forward]
Proved developed reserves (Energy) | MBoe	80	93	101	93
Noncontrolling Interest | Crude Oil and Condensate | Egypt
Reserve Quantities [Line Items]
Proved developed reserves	47,000	53,000	54,000	48,000
Noncontrolling Interest | Natural Gas Liquids | Egypt
Reserve Quantities [Line Items]
Proved developed reserves	241	466	523	519
Noncontrolling Interest | Natural Gas | Egypt
Reserve Quantities [Line Items]
Proved developed reserves | MMcf	196,000	239,000	277,000	270,000