Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Taxes [Abstract]

Components of Income (Loss) from Continuing Operations Before Income Taxes and Income Tax Expense

(Thousands of dollars)	2016		2015	2014
Income (loss) from continuing operations before income taxes
United States	$	(595,196)	(1,259,268)	179,484
Foreign		102,081	(2,022,994)	1,072,786
Total	$	(493,115)	(3,282,262)	1,252,270
Income tax expense (benefit)
Federal – Current	$	-	(9,435)	25,151
– Deferred		(197,450)	(241,127)	25,444
		(197,450)	(250,562)	50,595
State		13,984	(5,294)	8,840
Foreign – Current		146,861	(40,550)	359,502
– Deferred		(182,567)	(730,084)	(191,640)
		(35,706)	(770,634)	167,862
Total	$	(219,172)	(1,026,490)	227,297

Effective Income Tax Rates

(Thousands of dollars)	2016		2015	2014
Income tax expense (benefit) based on the U.S. statutory tax rate	$	(172,590)	(1,148,792)	438,295
Foreign income (loss) subject to foreign tax rates different than      the U.S. statutory rate		8,582	49,739	20,562
State income taxes, net of federal benefit		9,090	(3,441)	5,746
U.S. tax benefit on certain foreign upstream investments		(21,336)	(16,939)	(95,838)
Current tax on distribution of foreign earnings		–	–	52,724
Deferred tax on distribution of foreign earnings		–	188,461	–
Tax effects on sale of Canadian assets		(89,473)	–	–
Tax effects on sale of Malaysian assets		2,080	(122,559)	(227,241)
Increase in deferred tax asset valuation allowance related      to other foreign exploration expenditures		25,734	40,788	37,712
Other, net		18,741	(13,747)	(4,663)
Total	$	(219,172)	(1,026,490)	227,297

Analysis of Deferred Tax Assets and Deferred Tax Liabilities Showing Tax Effects of Significant Temporary Differences

(Thousands of dollars)	2016		2015
Deferred tax assets
Property and leasehold costs	$	572,481	587,517
Liabilities for dismantlements		170,946	114,565
Postretirement and other employee benefits		214,288	226,217
Alternative minimum tax		29,710	39,683
Foreign tax credit carryforwards		33,295	855
U. S. net operating loss		454,231	–
Other deferred tax assets		16,541	127,165
Total gross deferred tax assets		1,491,492	1,096,002
Less valuation allowance		(305,389)	(294,406)
Net deferred tax assets		1,186,103	801,596
Deferred tax liabilities
Accumulated depreciation, depletion and amortization		(867,343)	(793,972)
Other deferred tax liabilities		(21,908)	(21,095)
Total gross deferred tax liabilities		(889,251)	(815,067)
Net deferred tax assets (liabilities)	$	296,852	(13,471)

Reconciliation of Beginning and Ending Amount of Consolidated Liability for Unrecognized Income Tax Benefits

(Thousands of dollars)	2016		2015	2014
Balance at January 1	$	6,631	6,011	6,366
Additions for tax positions related to current year		756	821	988
Settlements due to lapse of time		–	–	(1,225)
Foreign currency translation effect		30	(201)	(118)
Balance at December 31	$	7,417	6,631	6,011