Long-Term Debt - Maturities Of Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Less than one year	$ 43,133
One to two years	38,539
Two to three years	8,965
Three to four years	209,412
Four to five years	9,881
Gross debt	309,930	$ 313,850
Unamortized debt issuance costs	(8,317)
Total debt	301,613
Less: current maturities	(43,117)	(42,873)
Long-term debt	258,496	262,137
Convertible Senior Notes Maturing May 2022
Debt Instrument [Line Items]
Less than one year	35,000
Gross debt	35,000	35,000
Unamortized debt issuance costs	(16)
Total debt	34,984
Less: current maturities	(34,984)
Convertible Senior Notes Maturing September 2023
Debt Instrument [Line Items]
One to two years	30,000
Gross debt	30,000	30,000
Unamortized debt issuance costs	(270)
Total debt	29,730
Long-term debt	29,730
Convertible Senior Notes Maturing February 2026
Debt Instrument [Line Items]
Three to four years	200,000
Gross debt	200,000	200,000
Unamortized debt issuance costs	(5,592)
Total debt	194,408
Long-term debt	194,408
MARAD Debt Maturing February 2027
Debt Instrument [Line Items]
Less than one year	8,133
One to two years	8,539
Two to three years	8,965
Three to four years	9,412
Four to five years	9,881
Gross debt	44,930	$ 48,850
Unamortized debt issuance costs	(2,439)
Total debt	42,491
Less: current maturities	(8,133)
Long-term debt	$ 34,358

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 issuance costs classified as noncurrent. 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. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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