(5) Long-Term Debt

Long-term debt at December 31, 2014 and 2013 consisted of the following (in thousands):

	2014		2013
Long-term debt, including current portion:
$150,000,000 senior notes Series A due February 27, 2020	$	150,000	$	150,000
$350,000,000 senior notes Series B due February 27, 2023		350,000		350,000
$540,000,000 term loan due July 1, 2016		100,000		208,000
$325,000,000 revolving credit facility due November 9, 2015		116,700		41,150
$10,000,000 credit line due June 29, 2015		—		—
	$	716,700	$	749,150

The aggregate payments due on the long-term debt in each of the next five years were as follows (in thousands):

2015	$	116,700
2016		100,000
2017		—
2018		—
2019		—
Thereafter		500,000
	$	716,700

The Company has $500,000,000 of unsecured senior notes (“Senior Notes Series A” and “Senior Notes Series B”) with a group of institutional investors, consisting of $150,000,000 of 2.72% Senior Notes Series A due February 27, 2020 and $350,000,000 of 3.29% Senior Notes Series B due February 27, 2023. The Company issued $82,500,000 of Senior Notes Series A and $192,500,000 of Senior Notes Series B on December 13, 2012, the proceeds of which were used to fund the acquisition of Penn Maritime, Inc. (“Penn”). The Company issued $67,500,000 of Senior Notes Series A and $157,500,000 of Senior Notes Series B on February 27, 2013, the proceeds of which were used to refinance $200,000,000 of floating rate senior notes due February 28, 2013, with the balance used to pay down the Company’s unsecured revolving credit facility. No principal payments are required until maturity. The Senior Notes Series A and Series B contain certain covenants on the part of the Company, including an interest coverage covenant, a debt-to-capitalization covenant and covenants relating to liens, asset sales and mergers, among others. The Senior Notes Series A and Series B also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others. As of December 31, 2014, the Company was in compliance with all Senior Notes Series A and Series B covenants and had $150,000,000 of Senior Notes Series A outstanding and $350,000,000 of Senior Notes Series B outstanding.

The Company has a $325,000,000 unsecured revolving credit facility (“Revolving Credit Facility”) with a syndicate of banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, with a maturity date of November 9, 2015. The variable interest rate spread varies with the Company’s senior debt rating and is currently 1.5% over the London Interbank Offered Rate (“LIBOR”) or 0.5% over an alternate base rate calculated with reference to the agent bank’s prime rate, among other factors (“Alternate Base Rate”). The commitment fee is currently 0.3%. The Revolving Credit Facility contains certain restrictive financial covenants including an interest coverage ratio and a debt-to-capitalization ratio. In addition to financial covenants, the Revolving Credit Facility contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates and changes in lines of business. Borrowings under the Revolving Credit Facility may be used for general corporate purposes, the purchase of existing or new equipment, the purchase of the Company’s common stock, or for business acquisitions. As of December 31, 2014, the Company was in compliance with all Revolving Credit Facility covenants and had $116,700,000 outstanding under the Revolving Credit Facility which was classified as current portion of long-term debt. The average borrowing under the Revolving Credit Facility during 2014 was $28,591,000, computing by averaging the daily balance, and the weighted average interest rate was 1.7%, computed by dividing the interest expense under the Revolving Credit Facility by the average Revolving Credit Facility borrowing. The Revolving Credit Facility includes a $25,000,000 commitment which may be used for standby letters of credit. Outstanding letters of credit under the Revolving Credit Facility were $4,939,000 as of December 31, 2014.

The Company has a credit agreement (“Term Loan”) with a group of commercial banks, with Wells Fargo Bank, National Association as the administrative agent bank, with a maturity date of July 1, 2016. The Term Loan provides for a $540,000,000 five-year unsecured term loan facility with a variable interest rate based on LIBOR or an Alternate Base Rate. The interest rate spread varies with the Company’s senior debt rating and is currently 1.5% over LIBOR or 0.5% over the Alternate Base Rate. The outstanding balance of the Term Loan is subject to quarterly amortization in increasing amounts and is prepayable, in whole or in part, without penalty. The Term Loan contains certain restrictive financial covenants including an interest coverage ratio and a debt-to-capitalization ratio. In addition to financial covenants, the Term Loan contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates and changes in lines of business. As of December 31, 2014, the Company was in compliance with all Term Loan covenants and had $100,000,000 outstanding under the Term Loan, none of which was classified as current portion of long-term debt. The average borrowing under the Term Loan during 2014 was $152,892,000, computed by averaging the daily balance, and the weighted average interest rate was 1.7%, computed by dividing the interest expense under the Term Loan by the average Term Loan borrowing.

The Company had $200,000,000 of unsecured floating rate senior notes (“Senior Notes”) that were retired on February 28, 2013, the maturity date of the Senior Notes, with the proceeds from the Senior Notes Series A and Senior Notes Series B described above.

The Company has a $10,000,000 line of credit (“Credit Line”) with Bank of America, N.A. (“Bank of America”) for short-term liquidity needs and letters of credit, with a maturity date of June 29, 2015. The Credit Line allows the Company to borrow at an interest rate agreed to by Bank of America and the Company at the time each borrowing is made or continued. The Company had no borrowings outstanding under the Credit Line as of December 31, 2014. Outstanding letters of credit under the Credit Line were $1,194,000 as of December 31, 2014.

The estimated fair value of total debt outstanding at December 31, 2014 and 2013 was $705,215,000 and $710,377,000, respectively, which differs from the carrying amount of $716,700,000 and $749,150,000, respectively, included in the consolidated financial statements. The fair value was determined using an income approach that relies on inputs such as yield curves.