4.   Leases

In April 2020, the FASB issued interpretive guidance relating to the accounting for lease concessions provided as a result of COVID-19. In this guidance, entities can elect not to apply lease modification accounting with respect to such lease concessions and instead, treat the concession as if it was a part of the existing contract. The Company has elected to not evaluate leases under the lease modification accounting framework for concessions that result from effects of the COVID-19 pandemic. In relation to our rights to use port facilities, we have elected the approach consistent with resolving a contingency, which allows us to remeasure the lease liability and recognize the amount of change in the lease liability as an adjustment to the carrying amount of the associated right-of-use asset. As the full amount of the concession will not be determinable until the force majeure period under the related arrangements have ended, periodic remeasurements will be required. During the contingency period, we are recognizing lease expense for these port facilities as incurred.

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Lease balances were as follows (in thousands):

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During the three and nine months ended September 30, 2021, right-of-use assets obtained in exchange for lease obligations were $501.4 million for operating leases to use certain port facilities. The leases had terms ranging from approximately 20 years to 32 years and incremental borrowing rates ranging from 4.3% to 5.8%.

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As of September 30, 2021, maturities of lease liabilities were as follows (in thousands):

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