Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total shipping revenues		$ 81,273	$ 100,859
Time and Bareboat Charter Revenues [Member]
Disaggregation of Revenue [Line Items]
Total shipping revenues		63,788	78,150
Voyage Charter Revenues [Member]
Disaggregation of Revenue [Line Items]
Total shipping revenues	[1]	7,037	11,468
Contracts of Affreightment Revenues [Member]
Disaggregation of Revenue [Line Items]
Total shipping revenues		$ 10,448	$ 11,241

[1] Voyage charter revenues include revenue related to short-term time charter contracts was $2,864 and $11,319 for the three months ended March 31, 2021 and 2020, respectively.