12.

Debt

Our debt consisted of the following (in millions):


As of December 31,	2015			2014
Long-term debt
1.450% Senior Notes due 2017	$	500.0		$	–
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			–
3.375% Senior Notes due 2021		300.0			300.0
3.150% Senior Notes due 2022		750.0			–
3.550% Senior Notes due 2025		2,000.0			–
4.250% Senior Notes due 2035		500.0			–
5.750% Senior Notes due 2039		500.0			500.0
4.450% Senior Notes due 2045		1,250.0			–
U.S. Term Loan		2,500.0			–
Japan Term Loan		96.8			98.0
Other long-term debt		4.6			4.9
Debt discount		(21.9	)		(1.4	)
Adjustment related to interest rate swaps		26.8			24.0

Total long-term debt	$	11,556.3		$	1,425.5

At December 31, 2015, our total debt consisted of $8.95 billion aggregate principal amount of our senior notes, a $2.5 billion U.S. term loan (“U.S. Term Loan”), an 11.7 billion Japanese Yen term loan agreement (“Japan Term Loan”) that will mature on May 31, 2018, and other debt, debt discount and fair value adjustments totaling $9.5 million.

The U.S. Term Loan is part of our $4.35 billion credit agreement (“Credit Agreement”) that contains: (i) a 5-year unsecured term loan facility in the principal amount of $3.0 billion (the “U.S. Term Loan Facility”), and (ii) a 5-year unsecured multicurrency revolving facility in the principal amount of $1.35 billion (the “Multicurrency Revolving Facility”). The Credit Agreement contains customary affirmative and negative covenants and events of default for an unsecured financing arrangement, including, among other things, limitations on consolidations, mergers and sales of assets. Financial covenants include a consolidated indebtedness to consolidated EBITDA ratio of no greater than 5.0 to 1.0 through June 24, 2016 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 Credit Agreement as of December 31, 2015.

On June 24, 2015, we borrowed $3.0 billion under the U.S. Term Loan Facility to fund a portion of the Biomet merger. Under the terms of the U.S. Term Loan Facility, 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. In 2015, we paid $500.0 million in principal under the U.S. Term Loan Facility, resulting in $2.5 billion in outstanding borrowings as of December 31, 2015. Due to the $500.0 million of advanced payments in 2015 on the U.S. Term Loan Facility, we have no quarterly principal obligations in 2016.

Borrowings under the Multicurrency Revolving Facility may be used for general corporate purposes. There were no borrowings outstanding under the Multicurrency Revolving Facility as of December 31, 2015.

Of the total $8.95 billion aggregate principal amount of senior notes outstanding at December 31, 2015, we issued $7.65 billion of this amount in March 2015 (the “Merger Notes”), the proceeds of which were used 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. The Merger Notes consist of the following seven tranches: the 1.450% Senior Notes due 2017, the 2.000% Senior Notes due 2018, the 2.700% Senior Notes due 2020, 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.

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, the Merger Notes and the 3.375% Senior Notes due 2021 may be redeemed at our option without any make-whole premium at specified dates ranging from one month to six months in advance of the scheduled maturity date.

Between the Closing Date and June 30, 2015, we repaid the Biomet senior notes we assumed in the merger. The fair value of the principal amount plus interest was $2,798.6 million. These senior notes required us to pay a call premium in excess of the fair value of the notes when they were repaid. As a result, we recognized $22.0 million in non-operating other expense related to this call premium.

The estimated fair value of our senior notes as of December 31, 2015, based on quoted prices for the specific securities from transactions in over-the-counter markets (Level 2), was $8,837.5 million. The estimated fair value of the Japan Term Loan as of December 31, 2015, based upon publicly available market yield curves and the terms of the debt (Level 2), was $96.4 million. The carrying value of the U.S. Term Loan approximates fair value as it bears interest at short-term variable market rates.

We have 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. See Note 14 for additional information regarding the interest rate swap agreements.

We also have available uncommitted credit facilities totaling $35.8 million.

At December 31, 2015 and 2014, the weighted average interest rate for our long-term borrowings was 2.9 percent and 3.5 percent, respectively. We paid $207.1 million, $67.5 million and $68.1 million in interest during 2015, 2014 and 2013, respectively.