CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Shipping Revenues:
Shipping revenues	$ 125,337	$ 101,874
Operating Expenses:
Voyage expenses	5,606	7,845
Vessel expenses	32,960	30,538
Charter hire expenses	10,231	17,185
Depreciation and amortization	18,267	18,929
General and administrative	7,434	6,773
Provision for credit losses, net	62	1,298
Third-party debt modification fees	232	30
Gain on disposal of vessels and other property	(2,804)	(48)
Total operating expenses	71,988	82,550
Income from vessel operations	53,349	19,324
Equity in income of affiliated companies	5,111	8,070
Operating income	58,460	27,394
Other (expense)/income	(13,432)	1,036
Income before interest expense and income taxes	45,028	28,430
Interest expense	(12,009)	(17,533)
Income before income taxes	33,019	10,897
Net income	$ 33,019	$ 10,897
Weighted Average Number of Common Shares Outstanding:
Basic	29,154,639	29,181,233
Diluted	29,348,393	29,223,187
Per Share Amounts:
Basic net income per share	$ 1.13	$ 0.37
Diluted net income per share	$ 1.12	$ 0.37
Pool Revenue Leases [Member]
Shipping Revenues:
Shipping revenues	$ 101,209	$ 67,637
Time and Bareboat Charter Leases [Member]
Shipping Revenues:
Shipping revenues	8,604	5,520
Voyage Charter Leases [Member]
Shipping Revenues:
Shipping revenues	$ 15,524	$ 28,717