CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities:
Net loss	$ (5,626,000)	$ (48,112,000)
Items included in net loss not affecting cash flows:
Depreciation and amortization	37,747,000	34,428,000
Loss on write-down of vessels and other assets	0	948,000
Amortization of debt discount and other deferred financing costs	3,560,000	2,651,000
Deferred financing costs write-off		2,273,000
Stock compensation, non-cash	1,821,000	1,525,000
Earnings of affiliated companies	(16,367,000)	(17,548,000)
Other - net	227,000	233,000
Items included in net loss related to investing and financing activities:
Loss/(gain) on disposal of vessels and other property, net	1,500,000	(1,115,000)
Loss on repurchase of debt		1,295,000
Cash distributions from affiliated companies	6,528,000	35,863,000
Payments for drydocking	(10,878,000)	(2,701,000)
Insurance claims proceeds related to vessel operations	640,000	3,528,000
Changes in operating assets and liabilities:
Decrease/(increase) in receivables	20,163,000	(4,221,000)
Decrease in deferred revenue	(15,000)	(903,000)
Net change in inventories, prepaid expenses and other current assets, accounts payable, accrued expenses and other current and long-term liabilities	4,478,000	1,979,000
Net cash provided by operating activities	43,778,000	10,123,000
Cash Flows from Investing Activities:
Expenditures for vessels and vessel improvements	(5,356,000)	(128,925,000)
Proceeds from disposal of vessels and other property, net	9,090,000	126,504,000
Expenditures for other property	(301,000)	(320,000)
Investments in and advances to affiliated companies, net	434,000	1,966,000
Repayments of advances from affiliated companies	5,272,000	93,142,000
Net cash provided by investing activities	9,139,000	92,367,000
Cash Flows from Financing Activities:
Issuance of debt, net of issuance and deferred financing costs		72,924,000
Extinguishment of debt		(60,000,000)
Payments on debt	(19,652,000)	(42,770,000)
Cash paid to tax authority upon vesting of stock-based compensation	(359,000)	(397,000)
Other - net	(258,000)
Net cash used in financing activities	(20,269,000)	(30,243,000)
Net increase in cash, cash equivalents and restricted cash	32,648,000	72,247,000
Cash, cash equivalents and restricted cash at beginning of year	117,644,000	70,606,000
Cash, cash equivalents and restricted cash at end of period	$ 150,292,000	$ 142,853,000