Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Taxes [Abstract]

Components of Income from Continuing Operations Before Income Taxes and Income Tax Expense

(Thousands of dollars)	2015		2014	2013
Income (loss) from continuing operations before income taxes
United States	$	(1,259,268)	179,484	(5,810)
Foreign		(2,022,994)	1,072,786	1,478,497
Total	$	(3,282,262)	1,252,270	1,472,687
Income tax expense (benefit)
Federal – Current	$	(9,435)	25,151	(56,790)
– Deferred		(241,127)	25,444	65,883
		(250,562)	50,595	9,093
State		(5,294)	8,840	7,141
Foreign – Current		(40,550)	359,502	477,715
– Deferred		(730,084)	(191,640)	90,601
		(770,634)	167,862	568,316
Total	$	(1,026,490)	227,297	584,550

Effective Income Tax Rates

(Thousands of dollars)	2015		2014	2013
Income tax expense (benefit) based on the U.S. statutory tax rate	$	(1,148,792)	438,295	515,440
Foreign income (loss) subject to foreign tax rates different than      the U.S. statutory rate		49,739	20,562	31,752
State income taxes, net of federal benefit		(3,441)	5,746	4,642
U.S. tax benefit on certain foreign upstream investments		(16,939)	(95,838)	(133,526)
Current tax on distribution of foreign earnings		–	52,724	–
Deferred tax on distribution of foreign earnings		188,461	–	–
Tax effects on sale of Malaysian assets		(122,559)	(227,241)	–
Increase in deferred tax asset valuation allowance related      to other foreign exploration expenditures		40,788	37,712	129,588
Impairment or abandonment of Azurite field with no tax benefit		–	–	35,475
Other, net		(13,747)	(4,663)	1,179
Total	$	(1,026,490)	227,297	584,550

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

(Thousands of dollars)	2015		2014
Deferred tax assets
Property and leasehold costs	$	587,517	379,577
Liabilities for dismantlements		114,565	85,544
Postretirement and other employee benefits		226,217	208,600
Alternative minimum tax		39,683	46,792
Foreign tax credit carryforwards		855	44,061
Other deferred tax assets		127,165	22,426
Total gross deferred tax assets		1,096,002	787,000
Less valuation allowance		(294,406)	(306,463)
Net deferred tax assets		801,596	480,537
Deferred tax liabilities
Property, plant and equipment		–	(479,677)
Accumulated depreciation, depletion and amortization		(793,972)	(1,123,864)
Other deferred tax liabilities		(21,095)	(15,753)
Total gross deferred tax liabilities		(815,067)	(1,619,294)
Net deferred tax liabilities	$	(13,471)	(1,138,757)

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

(Thousands of dollars)	2015		2014	2013
Balance at January 1	$	6,011	6,366	16,611
Additions for tax positions related to current year		821	988	2,486
Settlements due to lapse of time		–	(1,225)	(12,731)
Foreign currency translation effect		(201)	(118)	–
Balance at December 31	$	6,631	6,011	6,366