Face (par) amount of debt instrument at time of issuance.

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- Definition

Amount of interest expense incurred on a debt or other obligation to related party.

+ References

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Amount of interest payable on debt, including, but not limited to, trade payables.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Related Party Disclosures (Details) - USD ($)	3 Months Ended		6 Months Ended
Related Party Disclosures (Details) - USD ($)	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Oct. 01, 2018
Related Party Transaction [Line Items]
Debt outstanding	$ 236,184,000		$ 236,184,000		$ 234,998,000
Notes
Related Party Transaction [Line Items]
Debt outstanding	136,527,000		136,527,000		135,131,000
Notes \| 3.50% Convertible Senior Notes due October 1, 2024
Related Party Transaction [Line Items]
Debt instrument face amount						$ 150,000,000
Debt outstanding	150,000,000		150,000,000		150,000,000
Interest accrued	1,313,000		1,313,000		$ 1,313,000
Interest expense on Notes	$ 1,313,000	$ 1,269,000	$ 2,625,000	$ 2,581,000