Long-term debt - Schedule of Future Payments Related to Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
2021, Principal	$ 3,129
2021, Interest	47,999
2021, Principal and Interest Total	51,128
2022, Principal	4,126
2022, Interest	47,796
2022, Principal and Interest Total	51,922
2023, Principal	219,204
2023, Interest	47,527
2023, Principal and Interest Total	266,731
2024, Principal	2,204
2024, Interest	32,949
2024, Principal and Interest Total	35,153
2025, Principal	553
2025, Interest	32,832
2025, Principal and Interest Total	33,385
Thereafter, Principal	556,871
Thereafter, Interest	50,632
Thereafter, Principal and Interest Total	607,503
Total payments, Principal	786,087
Total payments, Interest	259,735
Total payments, Principal and future interest expense	1,045,822
Interest	(259,735)
Deferred financing cost	(4,641)	$ (3,397)
Long term debt	776,574	$ 626,808
2023 Notes
Debt Instrument [Line Items]
Discount on Notes	(1,147)
Premium on Notes	427
2027 Notes
Debt Instrument [Line Items]
Discount on Notes	(7,358)
Premium on Notes	$ 3,206

Interest accrued in the future deducted for long term debt

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Long term debt, expected future interest expense

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Long-term Debt, Maturities, Repayments of Interest after Year Five

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Long-term Debt, Maturities, Repayments of Interest in Next Twelve Months

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Long-term Debt, Maturities, Repayments of Interest in Year Five

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Long-term Debt, Maturities, Repayments of Interest in Year Four

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Long-term Debt, Maturities, Repayments of Interest in Year Three

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Long-term debt, principal and future interest expense.

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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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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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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 of long-term debt and lease obligation, including portion classified as current.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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