(In thousands)	Maturity Dates	December 31, 2018		December 31, 2017
Unsecured private placement notes
3.95% (net of unamortized debt issuance cost of $360 and $346 for 2018 and 2017, respectively)	2021-2027	$	99,640	$	99,654
3.86% (net of unamortized debt issuance cost of $347 and $343 for 2018 and 2017, respectively)	2019-2025		99,653		99,657
4.86% (net of unamortized debt issuance cost of $186 and $191 for 2018 and 2017, respectively)	2018-2023		46,243		55,523
5.88% (net of unamortized debt issuance cost of $85 and $95 for 2018 and 2017, respectively)	2018-2022		22,772		28,476
5.69% (net of unamortized debt issuance cost of $0 and $12 for 2018 and 2017, respectively)	2018		—		5,703
Debt of foreign subsidiaries
Unsecured bank debt, foreign currency	2019		7,772		1,786
Total debt		$	276,080	$	290,799
Less current maturities			37,058		22,500
Long-term debt		$	239,022	$	268,299

The majority of the Company’s long-term debt financing is composed of unsecured private placement notes issued to insurance companies, totaling $269,286,000 as of December 31, 2018. These notes are denominated in U.S. dollars and have fixed interest rates ranging from 3.86 percent to 5.88 percent. The notes had original maturities of 12 years with mandatory amortization of principal beginning six years after issuance. The Company will be required to make amortization payments on the currently outstanding notes from 2019 to 2027.

On January 30, 2018, the Company entered into a five year committed $350,000,000 multi-currency revolving credit facility that matures on January 30, 2023 with a syndicate of banks. This credit facility replaced the Company’s prior $125,000,000 credit agreement. The Company’s outstanding Note Purchase Agreements were amended effective January 30, 2018 to make certain covenants consistent with those included in the revolving credit agreement. The Company maintains standby letters of credit under its workers’ compensation insurance agreements and for other purposes, as needed from time to time, which are issued under the revolving credit agreement. On December 31, 2018, the Company had outstanding letters of credit of $4,725,000 and no borrowings under the revolving credit agreement with $345,275,000 remaining available.

Loans under the credit agreement may be incurred, at the discretion of the Company, with terms to maturity of one to six months. The Company may choose from two interest rate options: (1) LIBOR applicable to each currency plus spreads ranging from 1.25 percent to 1.875 percent, depending on the Company’s net leverage ratio, or (2) the prime rate plus 0.25 percent to 0.875 percent, depending on the Company’s net leverage ratio. The credit agreement requires the Company to pay a commitment fee ranging from 0.15 percent to 0.325 percent per annum, which also depends on the Company’s net leverage ratio. The credit agreement requires the maintenance of certain financial ratios and compliance with certain other covenants that are similar to the Company’s existing debt agreements, including net worth, interest coverage and leverage financial covenants and limitations on restricted payments, indebtedness and liens.

In addition to the unsecured private placement notes and the revolving credit facility, the Company’s foreign subsidiaries had $7,772,000 of unsecured debt at December 31, 2018.

The Company’s loan agreements in the U.S. and Philippines contain provisions, which, among others, require maintenance of certain financial ratios and place limitations on additional debt, investments and payment of dividends. Based on the loan agreement provisions that place limitations on dividend payments, unrestricted retained earnings (i.e., retained earnings available for dividend distribution) were $190,442,000 and $190,495,000 at December 31, 2018, and 2017, respectively.

Debt at December 31, 2018, matures as follows: $37,058,000 in 2019; $29,286,000 in 2020; $43,572,000 in 2021; $43,573,000 in 2022; $37,857,000 in 2023 and $85,712,000 after 2023. Debt maturing in 2019 includes $29,286,000 of scheduled repayments under long-term debt agreements and $7,772,000 of debt of foreign subsidiaries under short-term working capital loans. These short-term loan agreements are routinely renewed, but could be supplemented or replaced, if necessary, by the Company’s $350,000,000 revolving credit agreement entered into on January 30, 2018.

Net interest expense for the years ended December 31, 2018, 2017 and 2016, comprised the following:

(In thousands)	2018		2017			2016
Interest expense	$	13,360	$	14,428		$	15,240
Interest income		(1,829)		(2,075	)		(1,247	)
		11,531		12,353			13,993
Capitalized interest		(760)		(909	)		(788	)
Interest expense, net	$	10,771	$	11,444		$	13,205