Vessels, Net (Table) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Balance	$ 1,383,605
Balance	1,313,560	$ 1,383,605
Cost
Property, Plant and Equipment [Line Items]
Balance	1,687,274	1,505,013
Additions	5,563	234,000
Disposals	(44,000)	(51,739)
Balance	1,648,837	1,687,274
Accumulated Depreciation
Property, Plant and Equipment [Line Items]
Balance	(303,669)	(254,970)
Additions	(32,402)	(56,052)
Disposals	794	7,353
Balance	(335,277)	(303,669)
Net Book Value
Property, Plant and Equipment [Line Items]
Balance	1,383,605	1,250,043
Additions		177,948
Additions	(26,839)
Disposals	(43,206)	(44,386)
Balance	$ 1,313,560	$ 1,383,605

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of decrease in accumulated depreciation, depletion and amortization as a result of sale or disposal of property, plant and equipment.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of divestiture of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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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 depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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