DEBT

12 Months Ended

Dec. 31, 2020

14. DEBT

Debt consists of the following as of December 31:


(In thousands)	2020		2020		2019		2019
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
3.84% Senior notes due 2021	100,000		102,173		100,000		102,079
3.70% Senior notes due 2023	202,500		211,790		202,500		207,882
3.85% Senior notes due 2025	90,000		97,429		90,000		93,838
4.24% Senior notes due 2026	200,000		224,390		200,000		213,126
4.05% Senior notes due 2028	67,500		75,440		67,500		71,260
4.11% Senior notes due 2028	90,000		101,047		90,000		95,607
3.10% Senior notes due 2030	150,000		155,805		—		—
3.20% Senior notes due 2032	150,000		155,048		—		—
Total debt	1,050,000		1,123,122		750,000		783,792
Debt issuance costs, net	(1,147)		(1,147)		(594)		(594)
Unamortized interest rate swap proceeds (1)	9,439		9,439		11,233		11,233
Total debt, net	1,058,292		1,131,414		760,639		794,431
Less: current portion of long-term debt	100,000		100,000		—		—
Total long-term debt	$	958,292	$	1,031,414	$	760,639	$	794,431

(1) Represents the gain from termination of the Corporation's interest rate swap agreements on its 3.85% and 4.24% Senior Notes in February 2016, which will be amortized into interest expense over the remaining terms of the respective notes.

The weighted-average interest rate of the Corporation's Revolving Credit Agreement in 2020 and 2019 was 1.4% and 3.3%, respectively.

The Corporation's total debt outstanding had a weighted-average interest rate of 3.4% and 3.7% in 2020 and 2019, respectively.

Aggregate maturities of debt are as follows:


(In thousands)
2021	$	100,000
2022	—
2023	202,500
2024	—
2025	90,000
Thereafter	657,500
Total	$	1,050,000

Interest payments of $31 million, $30 million, and $32 million were made in 2020, 2019, and 2018, respectively.

Revolving Credit Agreement

In October 2018, the Corporation amended the terms of its existing Credit Agreement (Credit Agreement) with a syndicate of financial institutions, led by Bank of America N.A., Wells Fargo, N.A., and JP Morgan Chase Bank, N.A.. The amended agreement, which provides the Corporation with a borrowing capacity of $500 million, extended the maturity date from November 2019 to October 2023 and expanded the accordion feature from $100 million to $200 million. The proceeds available under the Credit Agreement are to be used for working capital, internal growth initiatives, funding of future acquisitions, and general corporate purposes. As of December 31, 2020, the Corporation had $21 million in letters of credit supported by the credit facility and no borrowings outstanding under the credit facility. The unused credit available under the credit facility as of December 31, 2020 was $479 million, which the Corporation had the ability to borrow in full without violating its debt to capitalization covenant.

The Credit Agreement contains covenants that the Corporation considers usual and customary for an agreement of this type for comparable commercial borrowers, including a maximum consolidated debt to capitalization ratio of 60%. The Credit Agreement has customary events of default, such as non-payment of principal when due; nonpayment of interest, fees, or other amounts; cross-payment default and cross-acceleration.

Borrowings under the credit agreement accrue interest based on (i) Libor or (ii) a base rate of the highest of (a) the federal funds rate plus 0.5%, (b) BofA’s announced prime rate, or (c) the Eurocurrency rate plus 1%, plus a margin. The interest rate and level of facility fees are dependent on certain financial ratios, as defined in the Credit Agreement. The Credit Agreement also provides customary fees, including administrative agent and commitment fees. In connection with the Credit Agreement, the Corporation paid customary transaction fees that have been deferred and are being amortized over the term of the Credit Agreement.

Senior Notes

On August 13, 2020, the Corporation issued $300 million of Senior Notes (the “2020 Notes”), consisting of $150 million of 3.10% Senior Notes that mature on August 13, 2030 and $150 million of 3.20% Senior Notes that mature on August 13, 2032. The 2020 Notes are senior unsecured obligations, equal in right of payment to the Corporation’s existing senior indebtedness. The Corporation, at its option, can prepay at any time all or any part of the 2020 Notes, subject to a make-whole payment in accordance with the terms of the Note Purchase Agreement. In connection with the issuance of the 2020 Notes, the Corporation paid customary fees that have been deferred and are being amortized over the term of the 2020 Notes. Under the terms of the Note Purchase Agreements, the Corporation is required to maintain certain financial ratios, the most restrictive of which are a debt to capitalization limit of 60% and an interest coverage ratio of less than 3 to 1. The debt to capitalization ratio (as defined per the Notes Purchase Agreement and Credit Agreement) is calculated using the same formula for all of the Corporation’s debt agreements and is a measure of the Corporation’s indebtedness to capitalization, where capitalization equals debt plus equity. The 2020 Notes also contain a cross default provision with respect to the Corporation’s other senior indebtedness.

On February 26, 2013, the Corporation issued $500 million of Senior Notes (the “2013 Notes”). The 2013 Notes consisted of $225 million of 3.70% Senior Notes that mature on February 26, 2023, $100 million of 3.85% Senior Notes that mature on February 26, 2025, and $75 million of 4.05% Senior Notes that mature on February 26, 2028. $100 million of additional 4.11% Senior Notes were deferred and subsequently issued on September 26, 2013 that mature on September 26, 2028. On October 15, 2018, the Corporation made a discretionary $50 million prepayment on the $500 million 2013 Notes. The 2013 Notes are senior unsecured obligations, equal in right of payment to the Corporation’s existing senior indebtedness. The Corporation, at its option, can prepay at any time all or any part of the 2013 Notes, subject to a make-whole payment in accordance with the terms of the Note Purchase Agreement. In connection with the issuance of the 2013 Notes, the Corporation paid customary fees that have been deferred and are being amortized over the term of the 2013 Notes. The 2013 Notes also contain a cross default provision with respect to the Corporation’s other senior indebtedness.

On December 8, 2011, the Corporation issued $300 million of Senior Notes (the “2011 Notes”). The 2011 Notes consist of $100 million of 3.84% Senior Notes that mature on December 1, 2021 and $200 million of 4.24% Senior Series Notes that mature on December 1, 2026. The 2011 Notes are senior unsecured obligations, equal in right of payment to our existing senior indebtedness. The Corporation, at its option, can prepay at any time all or any part of our 2011 Notes, subject to a make-whole payment in accordance with the terms of the Note Purchase Agreement. In connection with the 2011 Notes, the Corporation paid customary fees that have been deferred and are being amortized over the term of the 2011 Notes. Under the Note Purchase Agreement, the Corporation is required to maintain certain financial ratios, the most restrictive of which is a debt to capitalization limit of 60%. The 2011 Notes also contain a cross default provision with our other senior indebtedness.As of December 31, 2020, the Corporation had the ability to borrow additional debt of $1.5 billion without violating our debt to capitalization covenant.