Debt and Credit Agreements

The Company’s debt and credit agreements consisted of the following:



(In thousands)	March 31, 2019			December 31, 2018
Total debt
6.51% weighted-average senior notes	$	124,000		$	124,000
5.58% weighted-average senior notes	175,000			175,000
3.65% weighted-average senior notes	925,000			925,000
Revolving credit facility	—			7,000
Unamortized debt issuance costs	(4,662		)	(4,896		)
	$	1,219,338		$	1,226,104

The borrowing base under the terms of the Company's revolving credit facility is redetermined annually in April. In addition, either the Company or the banks may request an interim redetermination twice a year or in connection with certain acquisitions or divestitures of oil and gas properties. At March 31, 2019, the Company had no borrowings outstanding under its revolving credit facility and had unused commitments of $1.8 billion.

At March 31, 2019, the Company was in compliance with all restrictive financial covenants for both its revolving credit facility and senior notes.

Subsequent Event

On April 22, 2019, the Company entered into a second amended and restated credit agreement (the amended and restated credit agreement). The borrowing base under the amended and restated credit agreement remained unchanged at $3.2 billion, while the available commitments were reduced to $1.5 billion. The maximum revolving credit available to the Company is the lesser of the available commitments or the difference of the borrowing base less the outstanding senior notes.

Interest rates under the amended and restated credit agreement are based on LIBOR or ABR indications, plus a margin which ranges from 50 to 125 basis points for ABR loans and 150 to 225 basis points for LIBOR loans when not in an Investment Grade Period (as defined in the amended and restated credit agreement) and from 12.5 to 75 basis points for ABR loans and 112.5 to 175 basis points for LIBOR loans during an Investment Grade Period. The commitment fee on the unused available credit is calculated at annual rates ranging from 30 basis points to 42.5 basis points when not in an Investment Grade Period and from 12.5 to 27.5 basis points during an Investment Grade Period. All other terms and conditions of the amended and restated credit agreement are generally consistent with the Company’s existing revolving credit facility, including debt covenants, which remain unchanged. The new revolving credit facility matures in April 2024. The maturity date can be extended by one year upon the agreement of the Company and lenders holding at least 50 percent of the commitments under the new revolving credit facility.

There are currently no borrowings outstanding under the amended and restated credit agreement.