Debt (Tables)

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Schedule of long-term debt

Long-term debt consisted of the following:

	December 31
Millions of dollars	2013		2012
3.5% senior notes due August 2023	$	1,098	$	—
6.15% senior notes due September 2019	997		997
7.45% senior notes due September 2039	995		995
4.75% senior notes due August 2043	898		—
6.7% senior notes due September 2038	800		800
1.0% senior notes due August 2016	600		—
3.25% senior notes due November 2021	498		498
4.5% senior notes due November 2041	498		498
2.0% senior notes due August 2018	400		—
5.9% senior notes due September 2018	400		400
7.6% senior debentures due August 2096	293		293
8.75% senior debentures due February 2021	184		184
Other	155		155
Total long-term debt	$	7,816	$	4,820