2.LONG-TERM DEBT

Debt at March 31, 2017 and December 31, 2016 consisted of the following:


	March 31, 2017						December 31, 2016
			Unamortized Debt		Long-term				Unamortized Debt		Long-term
(in thousands)	Principal		Issuance Costs		Debt, net		Principal		Issuance Costs		Debt, net
5.875% Senior Notes	$	750,000	$	(5,381)	$	744,619	$	750,000	$	(5,691)	$	744,309
4.375% Senior Notes		750,000		(6,119)		743,881		750,000		(6,370)		743,630
Total long-term debt	$	1,500,000	$	(11,500)	$	1,488,500	$	1,500,000	$	(12,061)	$	1,487,939

At March 31, 2017 and December 31, 2016, we had no bank debt outstanding.

Bank Debt

We have a senior unsecured revolving credit facility (“Credit Facility”) that matures October 16, 2020. The Credit Facility has aggregate commitments of $1.0 billion, with an option for us to increase aggregate commitments to $1.25 billion at any time. There is no borrowing base subject to the discretion of the lenders based on the value of our proved reserves under the Credit Facility. As of March 31, 2017, we had letters of credit outstanding under the Credit Facility of $2.5 million, leaving an unused borrowing availability of $997.5 million.

At our option, borrowings under the Credit Facility may bear interest at either (a) LIBOR plus 1.125 – 2.0% based on the credit rating for our senior unsecured long-term debt, or (b) a base rate (as defined in the credit agreement) plus 0.125 – 1.0%, based on the credit rating for our senior unsecured long-term debt. Unused borrowings are subject to a commitment fee of 0.125 – 0.35%, based on the credit rating for our senior unsecured long-term debt.

The Credit Facility contains representations, warranties, covenants, and events of default that are customary for investment grade, senior unsecured bank credit agreements, including a financial covenant for the maintenance of a defined total debt-to-capital ratio of no greater than 65%. As of March 31, 2017, we were in compliance with all of the financial and non-financial covenants.

At March 31, 2017 and December 31, 2016, we had $4.2 million and $4.5 million, respectively, of unamortized debt issuance costs associated with our Credit Facility, which were recorded as assets and included in Other assets on our Condensed Consolidated Balance Sheets. These costs are being amortized to interest expense ratably over the life of the Credit Facility.

Senior Notes

Each of our senior unsecured notes is governed by an indenture containing certain covenants, events of default, and other restrictive provisions with which we were in compliance as of March 31, 2017. The 5.875% notes are due in 2022 and the 4.375% notes are due in 2024. Interest on each of the senior notes is payable semiannually. The effective interest rate on the 5.875% notes and the 4.375% notes, including the amortization of debt issuance costs, is 6.04% and 4.50%, respectively.

Subsequent Events

On April 3, 2017, we commenced a cash tender offer to purchase any of our 5.875% notes for cash consideration of $1,031.67 per $1,000 principal amount of notes, plus any accrued and unpaid interest up to, but not including, the settlement date. The tender offer expired on April 7, 2017, with $253.5 million aggregate principal amount of the notes validly tendered. On April 10, 2017, we settled the tendered notes for $268.1 million, including accrued interest. On April 12, 2017, we delivered a redemption notice pursuant to the terms of the indenture for all 5.875% notes remaining outstanding. All such notes will be redeemed on or before May 12, 2017 for $1,029.38 per $1,000 principal amount of notes, plus any accrued and unpaid interest up to, but not including, the redemption date.

On April 10, 2017, we issued $750 million aggregate principal amount of 3.90% senior unsecured notes due May 15, 2027 at 99.748% of par to yield 3.93% per annum. We received $743.2 million in net proceeds, after deducting underwriting discounts. We estimate an additional $1.5 million of offering costs will be deducted from these net proceeds. The notes bear an interest rate of 3.90% and interest is payable semiannually on May 15 and November 15, with the first payment to be made November 15, 2017. Along with cash on hand, we used, and intend to use, the proceeds to fund the settlement of the tendered 5.875% notes and the redemption of the 5.875% notes, both as discussed above.