Debt (Tables)

3 Months Ended

Mar. 31, 2020

Debt Disclosure [Abstract]

Schedule of Debt

	Millions of Dollars
	March 31 2020			December 31 2019
2.450% Senior Notes due December 2024	$	300		300
3.605% Senior Notes due February 2025	500			500
3.550% Senior Notes due October 2026	500			500
3.750% Senior Notes due March 2028	500			500
3.150% Senior Notes due December 2029	600			600
4.680% Senior Notes due February 2045	450			450
4.900% Senior Notes due October 2046	625			625
Tax-exempt bonds due April 2020 and April 2021 at 1.465% and 1.85% at March 31, 2020, and December 31, 2019, respectively	75			75
Debt at face value	3,550			3,550
Net unamortized discounts and debt issuance costs	(34		)	(34	)
Total debt	3,516			3,516
Short-term debt	(25		)	(25	)
Long-term debt	$	3,491		3,491