At March 31, 2021 and December 31, 2020, debt consisted of the following (in thousands):

	March 31, 2021		December 31, 2020
Credit Agreement with Banks, described below	$	—	$	—
Finance Leases, described below		66,017		70,976
Total debt		66,017		70,976
Less: current portion of long-term debt		21,055		20,588
Long-term debt, less current portion	$	44,962	$	50,388

The Company’s liquidity needs arise primarily from capital investment in new equipment, land and structures, information technology and letters of credit required under insurance programs, as well as funding working capital requirements.

The Company is party to a revolving credit agreement with a group of banks to fund capital investments, letters of credit and working capital needs.

On February 5, 2019, the Company entered into the Sixth Amended and Restated Credit Agreement with its banking group (as amended, the Amended Credit Agreement). The amendment increased the amount of the revolver from $250 million to $300 million and extended the term until February 2024. The Amended Credit Agreement also has an accordion feature that allows for an additional $100 million availability, subject to certain conditions and availability of lender commitments. The amendment reduced the interest rate pricing. The Amended Credit Agreement provides for a LIBOR rate margin range from 100 basis points to 200 basis points, base rate margins from minus 50 basis points to plus 50 basis points, an unused portion fee from 17.5 basis points to 30 basis points and letter of credit fees from 100 basis points to 200 basis points, in each case based on the Company’s leverage ratio. Under the Amended Credit Agreement, the Company must maintain a minimum debt service coverage ratio set at 1.25 to 1.00 and a maximum leverage ratio set at 3.25 to 1.00. The Amended Credit Agreement provides for a pledge by the Company of certain land and structures, accounts receivable and other assets to secure indebtedness under this agreement. The Amended Credit Agreement contains certain customary representations and warranties, affirmative and negative covenants and provisions relating to events of default. Under the Amended Credit Agreement, if an event of default occurs, the banks will be entitled to take various actions, including the acceleration of amounts due.

At March 31, 2021, the Company had no outstanding borrowings and outstanding letters of credit of $28.8 million under the Amended Credit Agreement. At December 31, 2020, the Company had no outstanding borrowings and outstanding letters of credit of $27.2 million under the Amended Credit Agreement. The available portion of the Amended Credit Agreement may be used for general corporate purposes, including capital expenditures, working capital and letter of credit requirements as needed.

The Company is obligated under finance leases with seven-year original terms covering revenue equipment. Total liabilities recognized under finance leases were $66.0 million and $71.0 million as of March 31, 2021 and December 31, 2020, respectively. Amortization of assets held under the finance leases is included in depreciation and amortization expense. As of March 31, 2021 and December 31, 2020, approximately $97.3 million and $100.1 million of finance leased assets, net of depreciation, were included in Property and Equipment, respectively. The weighted average interest rates for the finance leases at March 31, 2021 and December 31, 2020 were 3.5 percent and 3.5 percent, respectively.

The principal maturities of long-term debt, including interest on finance leases, for the next five years (in thousands) are as follows:

	Amount
2021	$	17,170
2022		20,960
2023		15,409
2024		10,606
2025		5,453
Thereafter		927
Total		70,525
Less: Amounts Representing Interest on Finance Leases		4,508
Total	$	66,017