Debt

12 Months Ended

Dec. 31, 2019

Our total debt, including short-term borrowings and current maturities of long-term debt, consisted of the following:



	December 31
Millions of dollars	2019			2018
5.0% senior notes due November 2045	$	2,000		$	2,000
3.8% senior notes due November 2025	2,000			2,000
3.5% senior notes due August 2023	1,100			1,100
4.85% senior notes due November 2035	1,000			1,000
7.45% senior notes due September 2039	1,000			1,000
4.75% senior notes due August 2043	900			900
6.7% senior notes due September 2038	800			800
3.25% senior notes due November 2021	500			500
4.5% senior notes due November 2041	500			500
7.6% senior debentures due August 2096	300			300
8.75% senior debentures due February 2021	185			185
6.75% notes due February 2027	104			104
Other	28			47
Unamortized debt issuance costs and discounts	(90		)	(92		)
Total	10,327			10,344
Short-term borrowings and current maturities of long-term debt	(11		)	(32		)
Total long-term debt	$	10,316		$	10,312

Senior debt

All of our senior notes and debentures rank equally with our existing and future senior unsecured indebtedness, have semiannual interest payments and have no sinking fund requirements. We may redeem all of our senior notes from time to time or all of the notes of each series at any time at the applicable redemption prices, plus accrued and unpaid interest. Our 6.75% notes due February 2027, 7.6% senior debentures due August 2096 and 8.75% senior debentures due February 2021 may not be redeemed prior to maturity.

Revolving credit facilities

We have a revolving credit facility with a capacity of $3.5 billion, which expires in March 2024. The facility is for working capital or general corporate purposes. The full amount of the revolving credit facility was available as of December 31, 2019.

Debt maturities

Our long-term debt matures as follows: $11 million in 2020, $697 million in 2021, $4 million in 2022, $1.1 billion in 2023, no amounts in 2024, and the remainder thereafter.