Revenue recognition, Lessor Arrangements, Future Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract]
Remainder of 2021	$ 24,956
2022	49,951
2023	50,616
2024	51,442
2025	51,876
Thereafter	1,102,841
Total minimum lease receivable	1,331,682
Unguaranteed residual value	107,000
Gross investment in sales-type lease	1,438,682
Less: Unearned interest income	827,687
Less: Current expected credit losses	1,550
Net investment in leased vessel	609,445
Current portion of net investment in leased asset	3,337
Non-current portion of net investment in leased asset	606,108	$ 7,044
Operating lease, payments, fiscal year maturity [Abstract]
Reminder of 2021	143,806
2022	245,023
2023	144,016
2024	103,461
2025	25,961
Thereafter	0
Total	$ 662,267