6. Debt

Debt comprised the following at December 31, 2015 and 2014:

(In thousands)	Maturity Dates	December 31, 2015		December 31, 2014
Unsecured private placement notes
3.95%	2021-2027	$	100,000	$	—
3.86%	2019-2025		100,000		100,000
4.86%	2017-2023		65,000		65,000
5.88%	2016-2022		40,000		40,000
5.69%	2016-2018		17,142		22,857
6.86%	2015		—		4,284
Unsecured U.S. bank debt	2019		—		20,000
Debt of foreign subsidiaries
Unsecured bank debt, foreign currency	2016		4,810		12,043
Unsecured bank term loan, foreign currency	2021		3,724		4,840
Secured bank term loan, foreign currency	2015		—		2,723
Secured bank debt, foreign currency	2016		1,947		1,638
Unsecured bank debt, U.S. dollars	2015		—		546
Total debt		$	332,623	$	273,931
Less current maturities			18,806		27,034
Long-term debt		$	313,817	$	246,897

The majority of the Company’s long-term debt financing is composed of unsecured private placement notes issued to insurance companies, totaling $322,142,000 as of December 31, 2015. These notes are denominated in U.S. dollars and have fixed interest rates ranging from 3.86 percent to 5.88 percent. At inception, these notes had final maturities of 12 to 13 years with remaining amortization scheduled from 2016 to 2027.

On July 10, 2015, the Company completed the issuance of $100,000,000 of unsecured private placement debt. These notes bear interest at a fixed rate of 3.95% with interest to be paid semi-annually and with equal annual principal payments beginning on July 10, 2021, and continuing through final maturity on July 10, 2027. The proceeds of this debt are being used primarily for capital expenditures, for paying down existing debt in accordance with normal payment schedules and for other corporate purposes. The terms of the note agreement require the maintenance of certain financial ratios and covenants that are substantially identical to the Company’s existing long-term debt and customary events of default.

The Company has a committed $125,000,000 multi-currency five-year revolving credit agreement with JPMorgan Chase Bank, N.A., as administrative agent, and four U.S. banks named as lenders thereunder. This unsecured facility is the Company’s primary source of short-term borrowings, which the Company may draw on as needed to finance certain acquisitions, working capital and for general corporate purposes. This facility is secured through July 10, 2019.As of December 31, 2015, the Company had outstanding letters of credit of $4,700,000 and no borrowings under this agreement with $120,300,000 remaining available.

Loans under the credit agreement may be incurred, at the discretion of the Company, with terms to maturity of 1 to 180 days. The Company may choose from several interest rate options, including (1) LIBOR applicable to each currency plus spreads ranging from 0.975 percent to 1.525 percent, depending on the Company’s leverage ratio or (2) the prime rate plus zero percent to 0.525 percent, depending on the leverage ratio. The credit agreement requires the Company to pay a facility fee ranging from 0.150 percent to 0.350 percent, which also depends on the 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 $8,534,000 of unsecured debt and $1,947,000 of secured debt at December 31, 2015. The secured foreign debt is secured only by the assets of the respective entities.

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 $119,891,000 and $88,684,000 at December 31, 2015, and 2014, respectively.

Debt at December 31, 2015, matures as follows: $18,806,000 in 2016; $21,335,000 in 2017; $21,335,000 in 2018; $29,907,000 in 2019; $29,906,000 in 2020 and $211,334,000 after 2020. Debt maturing in 2016 includes $12,049,000 of scheduled repayments under long-term debt agreements and $6,757,000 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 $125,000,000 revolving credit agreement.

Net interest expense for the years ended December 31, 2015, 2014 and 2013, comprised the following:

(In thousands)	2015			2014			2013
Interest expense	$	15,488		$	12,542		$	11,104
Interest income		(217	)		(262	)		(57	)
		15,271			12,280			11,047
Capitalized interest		(738	)		(839	)		(689	)
Interest expense, net	$	14,533		$	11,441		$	10,358