(5) Long‑Term Debt

Long‑term debt was follows at December 31, 2013 and 2014 (in thousands):


	2013		2014
Antero:
Bank credit facility(a)	$	288,000		1,730,000
7.25% senior notes due 2019(c)		260,000		—
6.00% senior notes due 2020(d)		525,000		525,000
5.375% senior notes due 2021(e)		1,000,000		1,000,000
5.125% senior notes due 2022(f)		—		1,100,000
Net unamortized premium		5,999		7,550
	$	2,078,999		4,362,550
Antero Midstream Partners LP:
Bank credit facility(b)			$	—

(a) Senior Secured Revolving Credit Facility

Antero has a senior secured revolving bank credit facility (the “Credit Facility”) with a consortium of bank lenders. The maximum amount of the Credit Facility was $4.0 billion at December 31, 2014. Borrowings under the Credit Facility are subject to borrowing base limitations based on the collateral value of Antero’s proved properties and commodity hedge positions and are subject to regular semiannual redeterminations. At December 31, 2014, the borrowing base was $4.0 billion, including $500 million under the Water Facility, and lender commitments were $3.0 billion, including $200 million of commitments under the Water Facility. On February 17, 2015, lender commitments were increased to $4.0 billion, including $200 million of commitments under the Water Facility. The next redetermination of the borrowing base is scheduled to occur in October 2015. The maturity date of the Credit Facility is May 5, 2019.

On November 10, 2014, Antero and Antero Water entered into a new water credit facility (the “Water Facility”), in order to provide for separate borrowings attributable to Antero’s fresh water distribution business, which contains covenants that are substantially identical to those under the Credit Facility. In accordance with the Credit Facility and the Water Facility agreements, borrowings under the Water Facility reduce availability under the Credit Facility on a dollar-for-dollar basis. The Water Facility will mature at the earlier of the sale of Antero Water to Antero Midstream, the sale of Antero Water’s assets to Antero Midstream or May 12, 2016.

The Credit Facility and the Water Facility are ratably secured by mortgages on substantially all of Antero’s properties and guarantees from Antero’s restricted subsidiaries, as applicable. The Credit Facility and the Water Facility contain certain covenants, including restrictions on indebtedness and dividends, and, in the case of the Credit Facility, requirements with respect to working capital and interest coverage ratios. Interest is payable at a variable rate based on LIBOR or the prime rate, determined by Antero’s election at the time of borrowing. Antero was in compliance with all of the financial covenants under the Credit Facility as of December 31, 2013 and 2014.

As of December 31, 2014, Antero had a total outstanding balance under the Credit Facility and Water Facility of $1.73 billion, with a weighted average interest rate of 2.06%, and outstanding letters of credit of $387 million. As of December 31, 2013, Antero had an outstanding balance under the Credit Facility of $288 million, with a weighted average interest rate of 1.61%, and outstanding letters of credit of approximately $32 million. Commitment fees on the unused portion of the Credit Facility and the Water Facility are due quarterly at rates ranging from 0.375% to 0.50% of the unused facility based on utilization.

(b) Senior Secured Revolving Credit Facility – Antero Midstream Partners LP

On November 10, 2014, Antero Midstream entered into a senior secured revolving bank credit facility (the “Midstream Facility”) with a consortium of bank lenders. At December 31, 2014, the maximum amount of the facility was $1.0 billion. The maturity date of the Midstream Facility is November 10, 2019.

The Midstream Facility is ratably secured by mortgages on substantially all of the properties of Antero Midstream and guarantees from Antero Midstream or its subsidiary, as applicable. The Midstream Facility contains certain covenants, including restrictions on indebtedness and dividends and requirements with respect to leverage and interest coverage ratios. Interest is payable at a variable rate based on LIBOR or the prime rate, determined by election at the time of borrowing. Antero Midstream was in compliance with all of the financial covenants under the Midstream Facility as of December 31, 2014.

As of December 31, 2014, Antero Midstream did not have a balance outstanding under the Midstream Facility. Commitment fees on the unused portion of the Midstream Facility are due quarterly at rates ranging from 0.25% to 0.375% of the unused facility based on utilization.

On May 23, 2014, Antero redeemed the outstanding 7.25% senior notes due 2019 (the “2019 notes”) having a principal balance of $260 million at a redemption price of 100% of the principal amount plus a make-whole premium of $17.4 million. The make-whole premium, along with the write-off of $3 million of deferred financing costs, was charged to Loss on early extinguishment of debt in the accompanying statement of operations. The redemption was financed using a portion of the proceeds from the offering of Antero’s 5.125% senior notes due 2022 (the “2022 notes”) described below.

(d) 6.00% Senior Notes Due 2020

On November 19, 2012, Antero issued $300 million of 6.00% senior notes due December 1, 2020 at par. On February 4, 2013, Antero issued an additional $225 million of the 2020 notes at 103% of par. The 2020 notes are unsecured and effectively subordinated to the Credit Facility and the Water Facility to the extent of the value of the collateral securing such facilities. The 2020 notes rank pari passu to Antero’s other outstanding senior notes. The 2020 notes are guaranteed on a senior unsecured basis by Antero’s wholly-owned subsidiaries and certain of its future restricted subsidiaries. Interest on the 2020 notes is payable on June 1 and December 1 of each year. Antero may redeem all or part of the 2020 notes at any time on or after December 1, 2015 at redemption prices ranging from 104.500% on or after December 1, 2015 to 100.00% on or after December 1, 2018. In addition, on or before December 1, 2015, Antero may redeem up to 35% of the aggregate principal amount of the 2020 notes with the net cash proceeds of certain equity offerings, if certain conditions are met, at a redemption price of 106.00% of the principal amount of the 2020 notes, plus accrued interest. At any time prior to December 1, 2015, Antero may redeem the 2020 notes, in whole or in part, at a price equal to 100% of the principal amount of the 2020, notes plus a “make‑whole” premium and accrued interest. If Antero undergoes a change of control, the holders of the 2020 notes will have the right to require Antero to repurchase all or a portion of the notes at a price equal to 101% of the principal amount of the 2020 notes, plus accrued interest.

(e) 5.375% Senior Notes Due 2021

On November 5, 2013, Antero issued $1 billion of 5.375% senior notes due November 21, 2021 (the “2021 notes”) at par. The 2021 notes are unsecured and effectively subordinated to the Credit Facility and the Water Facility to the extent of the value of the collateral securing such facilities. The 2021 notes rank pari passu to Antero’s other outstanding senior notes. The 2021 notes are guaranteed on a full and unconditional and joint and several basis by Antero’s wholly-owned subsidiaries and certain of its future restricted subsidiaries. Interest on the 2021 notes is payable on May 1 and November 1 of each year. Antero may redeem all or part of the 2021 notes at any time on or after November 1, 2016 at redemption prices ranging from 104.031% on or after November 1, 2016 to 100.00% on or after November 1, 2019. In addition, on or before November 1, 2016, Antero may redeem up to 35% of the aggregate principal amount of the 2021 notes with the net cash proceeds of certain equity offerings, if certain conditions are met, at a redemption price of 105.375% of the principal amount of the 2021 notes, plus accrued interest. At any time prior to November 1, 2016, Antero may also redeem the 2021 notes, in whole or in part, at a price equal to 100% of the principal amount of the 2021 notes, plus a “make‑whole” premium and accrued interest. If Antero undergoes a change of control prior to May 1, 2015, it may redeem all, but not less than all, of the 2021 notes at a redemption price equal to 110% of the principal amount of the 2021 notes. If Antero undergoes a change of control, the holders of the 2021 notes will have the right to require Antero to repurchase all or a portion of the notes at a price equal to 101% of the principal amount of the 2021 notes, plus accrued interest.

(f) 5.125% Senior Notes Due 2022

On May 6, 2014, Antero issued $600 million of 5.125% senior notes due December 1, 2022 (the “2022 notes”) at par. On September 18, 2014, Antero issued an additional $500 million of the 2022 notes at 100.5% of par. The 2022 notes are unsecured and effectively subordinated to the Credit Facility and the Water Facility to the extent of the value of the collateral securing such facilities. The 2022 notes rank pari passu to Antero’s other outstanding senior notes. The 2022 notes are guaranteed on a full and unconditional and joint and several basis by Antero’s wholly-owned subsidiaries and certain of its future restricted subsidiaries. Interest on the 2022 notes is payable on June 1 and December 1 of each year. Antero may redeem all or part of the 2022 notes at any time on or after June 1, 2017 at redemption prices ranging from 103.844% on or after June 1, 2017 to 100.00% on or after June 1, 2020. In addition, on or before June 1, 2017, Antero may redeem up to 35% of the aggregate principal amount of the 2022 notes with the net cash proceeds of certain equity offerings, if certain conditions are met, at a redemption price of 105.125% of the principal amount of the 2022 notes, plus accrued interest. At any time prior to June 1, 2017, Antero may also redeem the 2022 notes, in whole or in part, at a price equal to 100% of the principal amount of the 2022 notes plus a “make-whole” premium and accrued interest. If Antero undergoes a change of control prior to December 1, 2015, it may redeem all, but not less than all, of the 2022 notes at a redemption price equal to 110% of the principal amount of the 2022 notes. If Antero undergoes a change of control, the holders of the 2022 notes will have the right to require Antero to repurchase all or a portion of the notes at a price equal to 101% of the principal amount of the 2022 notes, plus accrued interest.

(g) Treasury Management Facility

Antero has a stand‑alone revolving note with a lender under the Credit Facility which provides for up to $25.0 million of cash management obligations in order to facilitate Antero’s daily treasury management. Borrowings under the revolving note are secured by the collateral for the revolving credit facility. Borrowings under the facility bear interest at the lender’s prime rate plus 1.0%. The note matures on June 1, 2015. At December 31, 2014, there were no outstanding borrowings under this facility.