The following table details the Company’s long-term debt at the respective principal amounts, net of unamortized debt issuance costs (in thousands):
| | | | | | | | | | | | | | March 31, | | December 31, | | 2018 | | 2017 | | 2017 | Senior unsecured notes: | | | | | | 5.375% senior notes due 2024 (1) | $ | 295,400 |
| | $ | — |
| | $ | 295,243 |
| 6.75% senior notes due 2021 (2) | — |
| | 196,721 |
| | — |
| | $ | 295,400 |
| | $ | 196,721 |
| | $ | 295,243 |
| | | | | | | Revolving unsecured credit facility, maturing 2022 | $ | 83,000 |
| | $ | 137,000 |
| | $ | 107,000 |
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| | (1) | As of March 31, 2018 and December 31, 2017, deferred debt issuance costs of $4.6 million and $4.8 million, respectively, are included as a direct deduction from the carrying amount of the senior unsecured notes due 2024 in the accompanying condensed consolidated balance sheets. |
| | (2) | As of March 31, 2017, deferred debt issuance costs of $3.3 million are included as a direct deduction from the carrying amount of the senior unsecured notes due 2021 in the accompanying condensed consolidated balance sheets. |
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