CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income/(loss)	$ 55,978,000	$ (293,614,000)	$ 283,960,000
(Loss)/income from discontinued operations	0	(292,555,000)	203,395,000
Net income/(loss) from continuing operations	55,978,000	(1,059,000)	80,565,000
Items included in net income/(loss) from continuing operations not affecting cash flows:
Depreciation and amortization	58,673,000	89,563,000	76,851,000
Vessel impairment charges	5,878,000	104,405,000	0
Amortization of debt discount and other deferred financing costs	5,167,000	6,005,000	5,154,000
Compensation relating to restricted stock, stock unit and stock option grants	2,388,000	7,441,000	3,580,000
Deferred income tax benefit	(59,047,000)	(67,394,000)	(69,564,000)
Undistributed earnings of affiliated companies	(91,000)	132,000	(399,000)
Deferred payment obligations on charters-in	0	0	590,000
Reorganization items, non-cash	(105,000)	5,198,000	(50,000)
Other – net	3,282,000	2,268,000	1,971,000
Items included in net income/(loss) related to investing and financing activities:
Loss on repurchases and extinguishment of debt	3,237,000	2,988,000	0
Loss on disposal of vessels and other property, net	7,322,000	127,000	207,000
Distributions from INSW	0	202,000,000	200,000,000
Payments for drydocking	(8,390,000)	(6,844,000)	(41,323,000)
SEC payment, bankruptcy and IRS claim payments	(5,000,000)	(7,136,000)	(8,343,000)
Deferred financing costs paid for loan modification	0	0	(4,220,000)
Changes in operating assets and liabilities:
(Increase)/decrease in receivables	(753,000)	(16,794,000)	6,502,000
(Increase)/decrease in income tax recoverable	(246,000)	323,000	54,637,000
(Decrease)/increase in deferred revenue	(4,639,000)	63,000	(3,034,000)
Net change in prepaid items and accounts payable, accrued expenses and other current and long-term liabilities	(20,035,000)	7,574,000	(26,791,000)
Net cash provided by operating activities	43,619,000	328,860,000	276,333,000
Cash Flows from Investing Activities:
Change in restricted cash	15,569,000	(5,261,000)	42,502,000
Expenditures for other property	(11,000)	(666,000)	(75,000)
Proceeds from disposal of vessels and other property	1,055,000	0	0
Other – net	0	0	(54,000)
Net cash provided by/(used in) investing activities	16,613,000	(5,927,000)	42,373,000
Cash Flows from Financing Activities:
Cash dividends paid	0	(31,910,000)	0
Payments on debt, including adequate protection payments	0	(54,345,000)	(6,030,000)
Repurchases and extinguishment of debt	(84,170,000)	(120,224,000)	(326,051,000)
Repurchases of common stock and common stock warrants	0	(119,343,000)	(3,633,000)
Tax withholding on share-based awards	(1,157,000)	0	0
Net cash used in financing activities	(85,327,000)	(325,822,000)	(335,714,000)
Net decrease in cash and cash equivalents	(25,095,000)	(2,889,000)	(17,008,000)
Cash and cash equivalents at beginning of year	191,089,000	193,978,000	210,986,000
Cash and cash equivalents at end of year	165,994,000	191,089,000	193,978,000
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash flows provided by operating activities	0	111,768,000	222,739,000
Cash flows provided by investing activities	0	25,202,000	114,163,000
Cash flows used in financing activities	0	(355,687,000)	(206,284,000)
Net (decrease)/increase in cash and cash equivalents from discontinued operations	$ 0	$ (218,717,000)	$ 130,618,000