8. External Debt and Financing Arrangements

In June 2016, the Company amended and restated its credit agreement to combine and rollover the existing revolving credit facility and term loan into a new standalone $1.25 billion revolving credit facility. This amendment and restatement of the credit agreement was a non-cash transaction for the Company. Terms and conditions of the credit agreement, including the total commitment amount, essentially remained the same. The revolving credit facility will mature in June 2021 and borrowings thereunder will be used for general corporate purposes. On December 31, 2017 and 2016, our outstanding borrowings under these facilities were $615.0 million and $540.0 million, respectively. At December 31, 2017 and 2016, the current portion of long-term debt was zero. Interest rates under the facility are variable based on LIBOR at the time of the borrowing and the Company’s long-term credit rating and can range from LIBOR + 0.9% to LIBOR + 1.5%. As of December 31, 2017, we were in compliance with all covenants under this facility. As a result of the refinancing, we wrote-off prepaid debt issuance costs of approximately $1.3 million as of June 30, 2016.

In June 2015, we issued $900 million of unsecured senior notes (“Senior Notes”) in a registered public offering. The Senior Notes consist of two tranches: $400 million of five-year notes due 2020 with a coupon of 3% and $500 million of ten-year notes due 2025 with a coupon of 4%. We used the proceeds from the Senior Notes offering to pay down our revolving credit facility and for general corporate purposes. On December 31, 2017 and 2016, the outstanding amount of the Senior Notes, net of underwriting commissions and price discounts, was $892.6 million and $891.1 million, respectively.

We currently have uncommitted bank lines of credit in China, which provide for unsecured borrowings for working capital of up to $23.5 million in aggregate, of which zero were outstanding, as of December 31, 2017 and 2016. The weighted-average interest rates on these borrowings were zero, 1.5% and 1.0% in 2017, 2016 and 2015 respectively.

The components of external long-term debt were as follows:



(In millions)	2017		2016
$400 million unsecured senior note due June 2020	$	398.3	$	397.6
$500 million unsecured senior note due June 2025		494.3		493.5
$1,250 million revolving credit agreement due June 2021		615.0		540.0
Total debt		1,507.6		1,431.1
Less: current portion		—		—
Total long-term debt	$	1,507.6	$	1,431.1

Senior Notes payments during the next five years as of December 31, 2017 are zero in 2018 through 2019, $400 million in 2020 and zero in 2021 through 2022.

In our debt agreements, there are normal and customary events of default which would permit the lenders to accelerate the debt if not cured within applicable grace periods, such as failure to pay principal or interest when due or a change in control of the Company. There were no events of default as of December 31, 2017.