Charter arrangements - Future charter payments (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Future Charter Payments [Abstract]
2018	$ 52,457
2019	16,061
2020	14,979
2021	7,417
2022	0
Thereafter	0
Net charter payments:	$ 90,915

Future Charter Payments Abstract

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Amount of future charter payments due in the next fiscal year following the latest fiscal year.

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Amount of future charter payments due in the fifth fiscal year following the latest fiscal year.

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Amount of future charter payments due in the fourth fiscal year following the latest fiscal year.

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Amount of future charter payments due in the third fiscal year following the latest fiscal year.

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Amount of future charter payments due in the second fiscal year following the latest fiscal year.

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Amount of future charter payments due after the fifth fiscal year following the latest fiscal year.

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Total of Future Charter Payments

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