Income Taxes (Tables)

6 Months Ended

Jun. 30, 2015

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

The following table summarizes the difference between income tax expense at the United States statutory rate of 35% and the income tax expense at effective worldwide tax rates for the respective periods:

	Three Months Ended June 30,						Six Months Ended June 30,
Millions of dollars	2015			2014			2015			2014
Earnings before income taxes	$	275		$	235		$	482		$	449
Income tax expense computed at United States statutory tax rate	96			82			169			157
U.S. foreign income items, net of credits	(11		)	(13		)	(13		)	(25		)
Valuation allowance release	—			(13		)	(58		)	(13		)
Foreign government tax incentive (including BEFIEX in 2014)	(4		)	(5		)	(8		)	(11		)
Other	9			(1		)	9			(8		)
Income tax expense computed at effective worldwide tax rates	$	90		$	50		$	99		$	100