11.

Debt

Our debt consisted of the following (in millions):

	As of December 31,
	2017			2016
Current portion of long-term debt
1.450% Senior Notes due 2017	$	-		$	500.0
U.S. Term Loan B		75.0			75.0
2.000% Senior Notes due 2018		1,150.0			-
Other short-term debt		-			0.6
Total short-term debt	$	1,225.0		$	575.6
Long-term debt
2.000% Senior Notes due 2018	$	-		$	1,150.0
4.625% Senior Notes due 2019		500.0			500.0
2.700% Senior Notes due 2020		1,500.0			1,500.0
3.375% Senior Notes due 2021		300.0			300.0
3.150% Senior Notes due 2022		750.0			750.0
3.550% Senior Notes due 2025		2,000.0			2,000.0
4.250% Senior Notes due 2035		253.4			253.4
5.750% Senior Notes due 2039		317.8			317.8
4.450% Senior Notes due 2045		395.4			395.4
1.414% Euro Notes due 2022		600.4			527.4
2.425% Euro Notes due 2026		600.4			527.4
U.S. Term Loan A		835.0			1,700.0
U.S. Term Loan B		600.0			675.0
Japan Term Loan A		103.2			99.6
Japan Term Loan B		187.9			-
Other long-term debt		4.1			4.2
Debt discount and issuance costs		(53.2	)		(65.8	)
Adjustment related to interest rate swaps		23.1			31.4
Total long-term debt	$	8,917.5		$	10,665.8

At December 31, 2017, our total debt consisted of $8.4 billion aggregate principal amount of senior notes, which included $1.2 billion of Euro-denominated senior notes (“Euro notes”), $835.0 million outstanding under a U.S. term loan (“U.S. Term Loan A”) that will mature on June 24, 2020, $675.0 million outstanding under a U.S. term loan (“U.S. Term Loan B”) that will mature on September 30, 2019, an 11.7 billion Japanese Yen term loan agreement (“Japan Term Loan A”) and a 21.3 billion Japanese Yen term loan agreement (“Japan Term Loan B”) that each will mature on September 27, 2022, and other debt and fair value adjustments totaling $27.2 million, partially offset by debt discount and issuance costs of $53.2 million.

On September 22, 2017, we entered into a term loan agreement for the Japan Term Loan B, and an amended and restated term loan agreement, which amended and restated the Japan Term Loan A loan agreement dated as of May 24, 2012, as amended as of October 31, 2014. As described above, the term loans under both of these agreements will mature on September 27, 2022. Each of these term loans bears interest at a fixed rate of 0.635 percent per annum.

On December 13, 2016, we completed the offering of €500 million aggregate principal amount of our 1.414% Euro notes due December 13, 2022 and €500 million aggregate principal amount of our 2.425% Euro notes due December 13, 2026. Interest is payable on each series of Euro notes on December 13 of each year until maturity.

In 2016, we also entered into U.S. Term Loan B and borrowed $750.0 million thereunder to repay outstanding borrowings under a previous multicurrency revolving facility incurred in connection with the acquisition of LDR.

In 2015, we issued senior notes and borrowed $3.0 billion under U.S. Term Loan A to finance a portion of the cash consideration payable in the Biomet merger, pay merger related fees and expenses and pay a portion of Biomet’s funded debt.

In 2016 and 2015, we used a portion of the funds received from the above-described note issuances and borrowings to repay other outstanding debt. The repayments resulted in debt extinguishment charges of $53.3 million and $22.0 million in 2016 and 2015, respectively, recorded as part of other expense, net.

We have a revolving credit and term loan agreement (the “2016 Credit Agreement”) and a first amendment to our credit agreement executed in 2014 (the “2014 Credit Agreement”). The 2016 Credit Agreement contains the U.S. Term Loan B and a five-year unsecured multicurrency revolving facility of $1.5 billion (the “Multicurrency Revolving Facility”). The Multicurrency Revolving Facility replaced the previous multicurrency revolving facility under the 2014 Credit Agreement and will mature on September 30, 2021, with two available one-year extensions at our discretion. The 2014 Credit Agreement also provided for the U.S. Term Loan A, which remains in effect.

Borrowings under the 2014 and 2016 Credit Agreements generally bear interest at floating rates based upon indices determined by the currency of the borrowing, or at an alternate base rate, in each case, plus an applicable margin determined by reference to our senior unsecured long-term credit rating, or, in the case of borrowings under the Multicurrency Revolving Facility only, at a fixed rate determined through a competitive bid process. We pay a facility fee on the aggregate amount of the Multicurrency Revolving Facility at a rate determined by reference to our senior unsecured long-term credit rating.

The 2016 Credit Agreement and 2014 Credit Agreement, as amended, contain customary affirmative and negative covenants and events of default for unsecured financing arrangements, including, among other things, limitations on consolidations, mergers and sales of assets. Financial covenants under the 2016 and 2014 Credit Agreements include a consolidated indebtedness to consolidated EBITDA ratio of no greater than 5.0 to 1.0 through June 30, 2017, and no greater than 4.5 to 1.0 thereafter. If our credit rating falls below investment grade, additional restrictions would result, including restrictions on investments and payment of dividends. We were in compliance with all covenants under the 2016 and 2014 Credit Agreements as of December 31, 2017. As of December 31, 2017, there were no borrowings outstanding under the Multicurrency Revolving Facility.

Under the terms of U.S. Term Loan A, starting September 30, 2015, principal payments are due as follows: $75.0 million on a quarterly basis during the first three years, $112.5 million on a quarterly basis during the fourth year, and $412.5 million on a quarterly basis during the fifth year. We have paid $2.165 billion in principal under U.S. Term Loan A, resulting in $835.0 million in outstanding borrowings as of December 31, 2017. The interest rate at December 31, 2017 was 2.9 percent on U.S. Term Loan A.

Under the terms of U.S. Term Loan B, future principal payments are due as follows: $75.0 million on September 30, 2018, with the remaining balance due on the U.S. Term Loan B maturity date of September 30, 2019. We have paid $75.0 million in principal under U.S. Term Loan B, resulting in $675.0 million outstanding on the U.S. Term Loan B as of December 31, 2017. The interest rate at December 31, 2017 was 2.6 percent on U.S. Term Loan B.

We may, at our option, redeem our senior notes, in whole or in part, at any time upon payment of the principal, any applicable make-whole premium, and accrued and unpaid interest to the date of redemption. In addition, we may redeem, at our option, the 2.700% Senior Notes due 2020, the 3.375% Senior Notes due 2021, the 3.150% Senior Notes due 2022, the 3.550% Senior Notes due 2025, the 4.250% Senior Notes due 2035 and the 4.450% Senior Notes due 2045 without any make-whole premium at specified dates ranging from one month to six months in advance of the scheduled maturity date.

The estimated fair value of our senior notes as of December 31, 2017, based on quoted prices for the specific securities from transactions in over-the-counter markets (Level 2), was $8,489.8 million. The estimated fair value of Japan Term Loan A and Japan Term Loan B, in the aggregate, as of December 31, 2017, based upon publicly available market yield curves and the terms of the debt (Level 2), was $290.0 million. The carrying values of U.S. Term Loan A and U.S. Term Loan B approximate fair value as they bear interest at short-term variable market rates.

We entered into interest rate swap agreements which we designated as fair value hedges of underlying fixed-rate obligations on our senior notes due 2019 and 2021. These fair value hedges were settled in 2016. In 2016, we entered into various variable-to-fixed interest rate swap agreements that were accounted for as cash flow hedges of U.S. Term Loan B. See Note 13 for additional information regarding the interest rate swap agreements.

We also have available uncommitted credit facilities totaling $58.4 million.

At December 31, 2017 and 2016, the weighted average interest rate for our borrowings was 2.9 percent and 2.8 percent, respectively. We paid $317.5 million, $363.1 million, and $207.1 million in interest during 2017, 2016, and 2015, respectively.