7. Debt

Our debt consisted of the following (in millions):


	March 31, 2017			December 31, 2016
Current portion of long-term debt
1.450% Senior Notes due 2017	$	500.0		$	500.0
U.S. Term Loan B		75.0			75.0
Multicurrency Revolving Facility		400.0			—
Other short-term debt		—			0.6

Total current portion of long-term debt	$	975.0		$	575.6


Long-term debt
2.000% Senior Notes due 2018		1,150.0			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		534.8			527.4
2.425% Euro Notes due 2026		534.8			527.4
U.S. Term Loan A		1,550.0			1,700.0
U.S. Term Loan B		675.0			675.0
Japan Term Loan		105.4			99.6
Other long-term debt		4.1			4.2
Debt discount and issuance costs		(62.2	)		(65.8	)
Adjustment related to interest rate swaps		29.3			31.4

Total long-term debt	$	10,537.8		$	10,665.8

At March 31, 2017, our total debt balance consisted of $8.74 billion aggregate principal amount of our senior notes, which included $1.1 billion of Euro-denominated senior notes (“Euro Notes”), $1.55 billion outstanding under a U.S. term loan (“U.S. Term Loan A”) that will mature on June 24, 2020, $750 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”) that will mature on May 31, 2018, and other debt and fair value adjustments totaling $33.4 million, partially offset by debt discount and issuance costs of $62.2 million.

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. We pay a facility fee on the aggregate amount of the Multicurrency Revolving Facility. 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 March 31, 2017. As of March 31, 2017, $400.0 million of borrowings was 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 $1.45 billion in principal under U.S. Term Loan A, resulting in $1.55 billion in outstanding borrowings as of March 31, 2017.

Under the terms of U.S. Term Loan B, principal payments are due as follows: $75.0 million on each of September 30, 2017 and 2018, with the remaining balance due on the maturity date of September 30, 2019. No amounts had been paid on the U.S. Term Loan B as of March 31, 2017.

The estimated fair value of our senior notes as of March 31, 2017, based on quoted prices for the specific securities from transactions in over-the-counter markets (Level 2), was $8,811.2 million. The estimated fair value of the Japan Term Loan as of March 31, 2017, based upon publicly available market yield curves and the terms of the debt (Level 2), was $105.1 million. The carrying value of the Multicurrency Revolving Facility, U.S. Term Loan A and U.S. Term Loan B approximate fair value as they bear interest at short-term variable market rates.