Debt

Our long-term debt, including current maturities, consisted of the following:



	December 31
Millions of dollars	2016			2015
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
6.15% senior notes due September 2019	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
2.0% senior notes due August 2018	400			400
5.9% senior notes due September 2018	400			400
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
7.53% notes due May 2017	45			45
3.375% senior notes due November 2022	—			1,250
2.7% senior notes due November 2020	—			1,250
1.0% senior notes due August 2016	—			600
Other	253			144
Unamortized debt issuance costs and discounts	(110		)	(132		)
Total	12,377			15,346
Current maturities	(163		)	(659		)
Total long-term debt	$	12,214		$	14,687

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 7.6% and 8.75% senior debentures may not be redeemed prior to maturity.

In conjunction with the termination of our merger agreement with Baker Hughes, we mandatorily redeemed $2.5 billion of the senior notes we had issued in November 2015 in contemplation of the transaction. We redeemed those notes in May 2016 using cash on hand at a price of 101% of their principal amount, plus accrued and unpaid interest. The notes redeemed included the $1.25 billion of 2.7% senior notes due in 2020 and $1.25 billion of 3.375% senior notes due in 2022. We also repaid $600 million of senior notes that matured in August 2016.

Revolving credit facilities

In July 2015, we entered into a new five-year revolving credit agreement with a capacity of $3.0 billion. The credit agreement is for working capital or general corporate purposes and expires on July 21, 2020. The full amount of the revolving credit facility was available as of December 31, 2016.

Debt maturities

Our long-term debt matures as follows: $163 million in 2017, $841 million in 2018, $1.0 billion in 2019, $24 million in 2020, $702 million in 2021 and the remainder in 2022 and thereafter.