Debt

Long-term debt, which excludes draws on revolving credit facilities, consists of the following unsecured senior debt:



	October 31, 2015							Outstanding
Maturity	Effective Rate		Coupon Rate		Outstanding			January 31, 2015			November 1, 2014
					(Dollars in Millions)
2021	4.81	%	4.00	%	$	650		$	650		$	650
2023	3.25	%	3.25	%	350			350			350
2023	4.78	%	4.75	%	300			300			300
2025	4.25	%	4.25	%	650			—			—
2029	7.36	%	7.25	%	99			200			200
2033	6.05	%	6.00	%	166			300			300
2037	6.89	%	6.88	%	150			350			350
2045	5.57	%	5.55	%	450			—			—
2017	—		—		—			650			650
	4.88	%			2,815			2,800			2,800
Unamortized debt discount					(5		)	(7		)	(7		)
Deferred financing costs					(18		)	(13		)	(14		)
Long-term debt					$	2,792		$	2,780		$	2,779

ASC No. 820, Fair Value Measurements and Disclosures, requires fair value measurements be classified in various pricing categories. Our long-term debt is classified as Level 1, financial instruments with unadjusted, quoted prices listed on active market exchanges. The estimated fair value of our long-term debt was $2.9 billion at October 31, 2015 and $3.1 billion at both January 31, 2015 and November 1, 2014.

In July 2015, we completed a cash tender offer for $767 million of senior unsecured debt. We recognized a $131 million loss on extinguishment of debt in the second quarter of 2015 which includes the $126 million bond tender premium paid to holders as a result of the tender offer and a $5 million non-cash write-off of deferred financing costs and original issue discounts associated with the extinguished debt.

Concurrent with the settlement of the tender offer, we exercised our right to redeem $318 million ($317 million, net of discount) of 6.25% notes due in 2017. The redemption was completed in August 2015 and included a $37 million "make-whole" premium and a $1 million non-cash write-off of deferred financing costs and original issue discounts associated with the extinguished debt which was expensed in the third quarter.

In July 2015, we issued $650 million of 4.25% notes due in July 2025 and $450 million of 5.55% notes due in July 2045. Both notes include semi-annual, interest-only payments beginning January 17, 2016. Proceeds of the issuances and cash on hand were used to pay the principal, premium and accrued interest of the debt which was settled in July and August 2015.

On July 1, 2015, we entered into an Amended and Restated Credit Agreement with various lenders which provides for a $1.0 billion senior unsecured five-year revolving credit facility that will mature in June 2020. Among other things, the agreement includes a maximum leverage ratio financial covenant (which is consistent with the ratio under our prior credit agreement) and restrictions on liens and subsidiary indebtedness. As of October 31, 2015, the outstanding balance on the revolving credit facility was $400 million and the effective interest rate was 1.27%. The fair value of the short-term debt under the revolving credit facility approximates its carrying value due to the short-term nature of the agreement.