Long-Term Debt - Senior Notes Carrying Amount (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Details for the Senior Notes
Total	$ 680,385	$ 589,294
Senior Notes \| 6.125% Senior Notes
Details for the Senior Notes
Principal balance	550,000	550,000
Less: Debt issue cost	3,688	4,972
Less: debt discount	3,540	4,651
Total	$ 542,772	$ 540,377

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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