Debt

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



	December 31
Millions of dollars	2015			2014
5.0% senior notes due November 2045	$	2,000		$	—
3.8% senior notes due November 2025	2,000			—
3.375% senior notes due November 2022	1,250			—
2.7% senior notes due November 2020	1,250			—
3.5% senior notes due August 2023	1,100			1,100
4.85% senior notes due November 2035	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
1.0% senior notes due August 2016	600			600
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
Other	144			37
Unamortized debt issuance costs and discounts	(132		)	(92		)
Total	15,346			7,779
Current maturities	(659		)	(14		)
Total long-term debt	$	14,687		$	7,765

$7.5 billion issuance

In November 2015, we issued $7.5 billion aggregate principal amount of senior notes in five tranches: $1.25 billion of 2.7% senior notes due 2020, $1.25 billion of 3.375% senior notes due 2022, $2.0 billion of 3.8% senior notes due 2025, $1.0 billion of 4.85% senior notes due 2035, and $2.0 billion of 5.0% senior notes due 2045. We intend to use the net proceeds of the offering for general corporate purposes, including financing a portion of the cash consideration component of our pending acquisition of Baker Hughes. The 2020 notes and the 2022 notes, which aggregate $2.5 billion in principal amount, are subject to a special mandatory redemption. In the event the Baker Hughes acquisition is not consummated on or prior to November 13, 2016, or, if prior to such date, the merger agreement is terminated for any reason, we will be required to redeem the 2020 notes and the 2022 notes at a redemption price equal to 101% of the principal amount, plus accrued and unpaid interest. Based on management's assessment, we believe the 2020 notes and the 2022 notes are appropriately classified as long-term debt on our consolidated balance sheets as of December 31, 2015.

In conjunction with the November 2015 debt issuance, we adopted a new accounting standards update requiring debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. We applied the change retrospectively for prior period balances of unamortized debt issuance costs. As such, the table above now presents unamortized debt issuance costs and discounts in the aggregate for both periods. See Note 16 for further information.

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.

Revolving credit facilities

In July 2015, we entered into a new five-year revolving credit agreement, with an initial capacity of $3.0 billion, increasing to $4.5 billion upon closing of the Baker Hughes acquisition and satisfaction of the conditions provided in the credit agreement. 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, 2015.

Debt maturities

Our long-term debt matures as follows: $659 million in 2016, $79 million in 2017, $823 million in 2018, $1.0 billion in 2019, $1.3 billion in 2020, and the remainder in 2021 and thereafter.

Bridge facility commitment

In November 2014, we obtained a commitment letter for an $8.6 billion senior unsecured bridge facility in connection with the pending acquisition of Baker Hughes. Upon issuance of the $7.5 billion principal amount of senior notes in November 2015, the commitment was reduced by that amount to $1.1 billion, and the facility expires on April 30, 2016. We have not drawn any amounts under this commitment as of December 31, 2015. We may use cash on hand, obtain additional debt financings or a combination thereof, in lieu of utilizing all or a portion of the bridge facility for the remaining portion of the cash consideration for the acquisition. See Note 2 for further information about the pending acquisition.