Debt and Credit Arrangements

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Debt and Credit Arrangements

5. DEBT AND CREDIT ARRANGEMENTS

Debt consists of the following:

DECEMBER 31	2023			2022
(in millions)
Senior debentures maturing April 15, 2026	$	375.0		$	375.0
Senior debentures maturing September 1, 2030		300.0			300.0
Senior debentures maturing October 15, 2025		61.8			61.8
Subordinated debentures maturing February 3, 2027		50.1			50.1
Total principal debt		786.9			786.9
Unamortized debt issuance costs		(3.7	)		(4.5	)
Total	$	783.2		$	782.4

The Company held $375.0 million par value of 4.5% unsecured senior debentures at December 31, 2023 and 2022, that were issued on April 8, 2016, and mature on April 15, 2026. The Company also held $300.0 million aggregate principal amount of 2.50% unsecured senior debentures, issued on August 24, 2020 and maturing September 1, 2030 at December 31, 2023 and 2022. Additionally, the Company had outstanding 7.625% unsecured senior debentures with a par value of $61.8 million as of December 31, 2023 and 2022, maturing on October 15, 2025. All of the Company’s outstanding senior debentures are subject to certain restrictive covenants, including limitations on the issuance or disposition of stock of restricted subsidiaries and limitations on liens, and pay interest semi-annually.

The Company also held subordinated debentures with a par value of $50.1 million as of December 31, 2023 and 2022, maturing February 3, 2027, and pay cumulative dividends semi-annually at 8.207%.

Membership in FHLB provides the Company with access to additional short-term liquidity based on the level of investment in FHLB stock and pledged collateral. Total holdings of FHLB stock were $6.1 million and $6.0 million at December 31, 2023 and 2022, respectively. At December 31, 2023 and 2022, the Company had pledged government agency securities with a fair value of $153.0 million and $132.5 million, respectively, as collateral for periodic short-term borrowings with the FHLB. There were no borrowings outstanding with the FHLB at December 31, 2023 or 2022.

In July 2023, the Company entered into a $150.0 million credit agreement that provides for a five-year unsecured revolving credit facility. Concurrent with the Company's entry into this agreement, THG voluntarily terminated its existing $200.0 million credit agreement, dated April 30, 2019. The Company had no borrowings under the current credit agreement as of December 31, 2023. During 2023, the Company did not have any borrowings under the current agreement or the prior credit agreement.

Interest expense was $34.1 million, $34.1 million, and $34.0 million in 2023, 2022 and 2021, respectively. At December 31, 2023, the Company was in compliance with the covenants associated with all of its debt indentures and credit arrangements.