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Intangible Assets and Goodwill - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]      
Weighted-average amortization period of intangible assets consisted of time-charter contracts 20 years 8 months 12 days 20 years 8 months 12 days  
Amortization of intangible assets $ 8,900,000 $ 8,900,000 $ 8,900,000
Amortization expense of intangible assets, 2020 8,900,000    
Amortization expense of intangible assets, 2021 8,900,000    
Amortization expense of intangible assets, 2022 8,400,000    
Amortization expense of intangible assets, 2023 6,200,000    
Amortization expense of intangible assets, 2024 4,500,000    
Goodwill impairment $ 0 $ 800,000 $ 0