International Seaways (INSW) 10-Q 5 May 23 2023 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 05, 2023
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2023
Entity Registrant Name	INTERNATIONAL SEAWAYS, INC.
Entity Incorporation, State or Country Code	1T
Entity File Number	1-37836-1
Entity Tax Identification Number	98-0467117
Entity Address, Address Line One	600 Third Avenue
Entity Address, Address Line Two	39th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10016
City Area Code	212
Local Phone Number	578-1600
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		49,229,944
Entity Central Index Key	0001679049
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
Amendment Flag	false
Common Stock [Member]
Title of 12(b) Security	Common Stock (no par value)
Trading Symbol	INSW
Security Exchange Name	NYSE
Rights To Purchase Common Stock [Member]
Title of 12(b) Security	Rights to Purchase Common Stock
Trading Symbol	N/A
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 156,220	$ 243,744
Short-term investments	105,000	80,000
Restricted cash	18,329	0
Voyage receivables, net of allowance for credit losses of $123 and $261 including unbilled receivables of $238,212 and $279,567	248,029	289,775
Other receivables	11,559	12,583
Inventories	698	531
Prepaid expenses and other current assets	16,491	8,995
Current portion of derivative asset	6,274	6,987
Total Current Assets	562,600	642,615
Vessels and other property, less accumulated depreciation of $353,314 and $331,903	1,775,653	1,680,010
Vessels construction in progress	85,662	123,940
Deferred drydock expenditures, net	72,874	65,611
Operating lease right-of-use assets	7,085	8,471
Finance lease right-of-use assets	22,001	44,391
Pool working capital deposits	34,076	35,593
Long-term derivative assets	2,138	4,662
Other assets	9,441	10,041
Total Assets	2,571,530	2,615,334
Current Liabilities:
Accounts payable, accrued expenses and other current liabilities	53,197	51,069
Current portion of operating lease liabilities	430	1,596
Current portion of finance lease liabilities	18,326	41,870
Current installments of long-term debt	155,525	162,854
Total Current Liabilities	227,478	257,389
Long-term operating lease liabilities	7,738	7,740
Long-term debt	777,154	860,578
Other liabilities	1,877	1,875
Total Liabilities	1,014,247	1,127,582
Commitments and contingencies
Equity:
Capital - 100,000,000 no par value shares authorized; 49,171,314 and 49,120,648 shares issued and outstanding	1,501,516	1,502,235
Accumulated deficit	52,865	(21,447)
Stockholders Equity Subtotal	1,554,381	1,480,788
Accumulated other comprehensive income	2,902	6,964
Total Equity	1,557,283	1,487,752
Total Liabilities and Equity	$ 2,571,530	$ 2,615,334

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED BALANCE SHEETS [Abstract]
Unbilled voyage receivable (in dollars)	$ 238,212	$ 279,567
Voyage receivables, allowance for credit losses	123	261
Vessels and other property, accumulated depreciation	$ 353,314	$ 331,903
Common stock, shares authorized	100,000,000	100,000,000
Common stock, no par value	$ 0	$ 0
Common stock, shares, issued	49,171,314	49,120,648
Common stock, shares, outstanding	49,171,314	49,120,648

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Shipping Revenues:
Shipping revenues	$ 287,130	$ 101,482
Operating Expenses:
Voyage expenses	3,810	3,507
Vessel expenses	58,769	60,317
Charter hire expenses	8,800	7,309
Depreciation and amortization	29,548	27,000
General and administrative	11,246	10,166
Third-party debt modification fees	407	187
Gain on disposal of vessels and other assets, net of impairments	(10,748)	(1,376)
Total operating expenses	101,832	107,110
Income/(loss) from vessel operations	185,298	(5,628)
Equity in results of affiliated companies	0	5,597
Operating income/(loss)	185,298	(31)
Other income/(expense)	4,281	(226)
Income/(loss) before interest expense and income taxes	189,579	(257)
Interest expense	(16,947)	(12,740)
Income/(loss) before income taxes	172,632	(12,997)
Income tax benefit/(provision)	1	(4)
Net income/(loss)	172,633	(13,001)
Net income/(loss) attributable to the Company	$ 172,633	$ (13,001)
Weighted Average Number of Common Shares Outstanding:
Basic	49,138,613	49,571,337
Diluted	49,646,331	49,571,337
Per Share Amounts:
Basic net income/(loss) per share	$ 3.51	$ (0.26)
Diluted net income/(loss) per share	$ 3.47	$ (0.26)
Pool Revenue Leases [Member]
Shipping Revenues:
Shipping revenues	$ 259,578	$ 83,762
Time and Bareboat Charter Leases [Member]
Shipping Revenues:
Shipping revenues	13,150	6,175
Voyage Charter Leases [Member]
Shipping Revenues:
Shipping revenues	$ 14,402	$ 11,545

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Pool revenues, received from companies accounted for by the equity method	$ 91,707	$ 23,271

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) [Abstract]
Net income/(loss)	$ 172,633	$ (13,001)
Other comprehensive income/(loss), net of tax:
Net change in unrealized gains/(losses) on cash flow hedges	(3,838)	10,762
Defined benefit pension and other postretirement benefit plans:
Net change in unrecognized prior service costs	(30)	26
Net change in unrecognized actuarial losses	(194)	171
Other comprehensive (loss)/income, net of tax	(4,062)	10,959
Comprehensive income/(loss)	$ 168,571	$ (2,042)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash Flows from Operating Activities:
Net income/(loss)	$ 172,633	$ (13,001)
Items included in net income/(loss) not affecting cash flows:
Depreciation and amortization	29,548	27,000
Loss on write-down of vessels and other assets	0	1,697
Amortization of debt discount and other deferred financing costs	1,556	855
Amortization of time charter hire contracts acquired	0	340
Deferred financing costs write-off	166	133
Stock compensation	1,900	1,108
Earnings of affiliated companies	20	(5,597)
Other - net	(823)	580
Items included in net income/(loss) related to investing and financing activities:
Gain on disposal of vessels and other assets, net	(10,748)	(3,073)
Cash distributions from affiliated companies	0	2,250
Payments for drydocking	(12,978)	(17,570)
Insurance claims proceeds related to vessel operations	950	954
Changes in operating assets and liabilities:
Decrease/(increase) in receivables	41,746	(13,369)
Decrease in deferred revenue	(260)	0
Net change in inventories, prepaid expenses and other current assets and accounts payable, accrued expense, and other current and long-term liabilities	(2,888)	(2,088)
Net cash provided by/(used in) by operating activities	220,822	(19,781)
Cash Flows from Investing Activities:
Expenditures for vessels, vessel improvements and vessels under construction	(66,722)	(37,989)
Proceeds from disposal of vessels and other assets	20,021	24,257
Expenditures for other property	(524)	(390)
Investments in short term time deposits	(90,000)	0
Pool working capital deposits	0	(527)
Proceeds from maturities of short term time deposits	65,000	0
Net cash used in investing activities	(72,225)	(14,649)
Cash Flows from Financing Activities:
Repayments of debt	(137,449)	(46,265)
Proceeds from sale and leaseback financing, net of issuance and deferred financing costs	55,722	20,401
Payments on sale and leaseback financing and finance lease	(34,619)	(9,085)
Payments of deferred financing costs	(514)	0
Borrowings on revolving credit facilities	0	50,000
Cash dividends paid	(98,313)	(2,980)
Cash paid to tax authority upon vesting or exercise of stock-based compensation	(2,619)	(970)
Net cash (used in)/provided by financing activities	(217,792)	11,101
Net decrease in cash, cash equivalents and restricted cash	(69,195)	(23,329)
Cash, cash equivalents and restricted cash at beginning of year	243,744	98,933
Cash, cash equivalents and restricted cash at end of period	$ 174,549	$ 75,604

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Common Stock [Member] Restricted Stock	Common Stock [Member] Restricted Stock Units (RSUs) [Member]	Common Stock [Member]	Retained Earnings / (Accumulated deficit) [Member] Restricted Stock	Retained Earnings / (Accumulated deficit) [Member] Restricted Stock Units (RSUs) [Member]	Retained Earnings / (Accumulated deficit) [Member]	Accumulated Other Comprehensive Loss [Member] Restricted Stock	Accumulated Other Comprehensive Loss [Member] Restricted Stock Units (RSUs) [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member] Restricted Stock	Noncontrolling Interest [Member] Restricted Stock Units (RSUs) [Member]	Noncontrolling Interest [Member]	Restricted Stock	Restricted Stock Units (RSUs) [Member]	Total
Balance, beginning at Dec. 31, 2021			$ 1,591,446			$ (409,338)			$ (12,360)			$ 584			$ 1,170,332
Net income/(loss)			0			(13,001)			0			0			(13,001)
Other comprehensive income/(loss)			0			0			10,959			0			10,959
Dividends declared			(2,978)			0			0						(2,978)
Forfeitures of vested restricted stock awards			(970)			0			0			0			(970)
Compensation relating to restricted stock units awards	$ 296	$ 501		$ 0	$ 0		$ 0	$ 0		$ 0	$ 0		$ 296	$ 501
Compensation relating to stock option awards			311			0			0			0			311
Balance, ending at Mar. 31, 2022			1,588,606			(422,339)			(1,401)			584			1,165,450
Balance, beginning at Dec. 31, 2022			1,502,235			(21,447)			6,964						1,487,752
Net income/(loss)			0			172,633			0			0			172,633
Other comprehensive income/(loss)			0			0			(4,062)			0			(4,062)
Dividends declared			0			(98,321)			0			0			(98,321)
Forfeitures of vested restricted stock awards			(2,619)			0			0			0			(2,619)
Compensation relating to restricted stock units awards	$ 268	$ 1,412		$ 0	$ 0		$ 0	$ 0		$ 0	$ 0		$ 268	$ 1,412
Compensation relating to stock option awards			220			0			0			$ 0			220
Balance, ending at Mar. 31, 2023			$ 1,501,516			$ 52,865			$ 2,902						$ 1,557,283

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2023
BASIS OF PRESENTATION [Abstract]
BASIS OF PRESENTATION	Note 1 — Basis of Presentation: ​ The accompanying unaudited condensed consolidated financial statements include the accounts of International Seaways, Inc. (“INSW”), a Marshall Islands corporation, and its wholly owned subsidiaries. Unless the context indicates otherwise, references to “INSW”, the “Company”, “we”, “us” or “our”, refer to International Seaways, Inc. and its subsidiaries. As of March 31, 2023, the Company’s operating fleet consisted of 74 wholly-owned, finance leased or bareboat chartered-in and time-chartered-in oceangoing vessels, engaged primarily in the transportation of crude oil and refined petroleum products in the International Flag trade through its wholly owned subsidiaries. In addition to its operating fleet of 74 vessels, two dual-fuel LNG VLCC newbuilds are scheduled for delivery to the Company during the second quarter of 2023, bringing the total operating and newbuild fleet to 76 vessels as of March 31, 2023. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. They do not include all of the information and notes required by generally accepted accounting principles in the United States. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the results have been included. Operating results for the three months ended March 31, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023. ​ The condensed consolidated balance sheet as of December 31, 2022 has been derived from the audited financial statements at that date but does not include all of the information and notes required by generally accepted accounting principles in the United States for complete financial statements. For further information, refer to the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. ​ All intercompany balances and transactions within INSW have been eliminated. Investments in 50% or less owned affiliated companies, in which INSW exercises significant influence, are accounted for by the equity method. ​ Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no effect on the reported results of operations. An adjustment has been made to the condensed consolidated balance sheet for the fiscal year ended December 31, 2022 to reclassify $0.8 million from Pool working capital deposits (previously captioned as Investments in and advances to affiliated companies) to Other assets

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	Note 2 — Significant Accounting Policies: ​ For a description of all of the Company’s material accounting policies, see Note 2, “Summary of Significant Accounting Policies,” to the Company’s consolidated financial statements as of and for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K. The following is a summary of any changes or updates to the Company’s critical accounting policies for the current period: ​ Cash, cash equivalents and restricted cash — ​ Short-term investments ​ Concentration of Credit Risk — ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Allowance for Credit Losses - Balance at December 31, 2022 ​ $ 261 Reversal of expected credit losses ​ ​ (138) Balance at March 31, 2023 ​ $ 123 ​ During the three months ended March 31, 2023 and 2022, the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted in aggregate for 96% of consolidated voyage receivables at both March 31, 2023 and December 31, 2022, respectively. ​ Deferred finance charges — ​ Interest expense relating to the amortization of deferred financing charges amounted to $1.3 million and $0.6 million for the three months ended March 31, 2023 and 2022, respectively. ​ Vessels construction in progress — ​ Recently Issued Accounting Standards ​

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	3 Months Ended
	Mar. 31, 2023
EARNINGS PER COMMON SHARE [Abstract]
EARNINGS PER COMMON SHARE	Note 3 — Earnings per Common Share: ​ Basic earnings per common share is computed by dividing earnings, after the deduction of dividends and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. ​ The computation of diluted earnings per share assumes the issuance of common stock for all potentially dilutive stock options and restricted stock units not classified as participating securities. Participating securities are defined by ASC 260, Earnings Per Share ​ Weighted average shares of unvested restricted common stock considered to be participating securities totaled 48,890 and 87,117 for the three months ended March 31, 2023 and 2022, respectively. Such participating securities are allocated a portion of income, but not losses under the two-class method. As of March 31, 2023, there were 637,223 shares of restricted stock units and 257,310 stock options outstanding and considered to be potentially dilutive securities. ​ ​ ​ Reconciliations of the numerator of the basic and diluted earnings per share computations are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Net income/(loss) allocated to: ​ ​ ​ ​ ​ ​ Common Stockholders ​ $ 172,466 ​ $ (13,006) Participating securities ​ ​ 167 ​ ​ 5 ​ ​ $ 172,633 ​ $ (13,001) ​ For the three months ended March 31, 2023 earnings per share calculations, there was 507,718 dilutive equity awards outstanding. For the three months ended March 31, 2022 earnings per share calculations, there was no dilutive equity awards outstanding. Awards of 852,546 and 1,026,418 for the three months ended March 31, 2023 and 2022, respectively, were not included in the computation of diluted earnings per share because inclusion of these awards would be anti-dilutive. ​

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING	3 Months Ended
	Mar. 31, 2023
BUSINESS AND SEGMENT REPORTING [Abstract]
BUSINESS AND SEGMENT REPORTING	Note 4 — Business and Segment Reporting: ​ The Company has two reportable segments: Crude Tankers and Product Carriers. Adjusted income/(loss) from vessel operations for segment purposes is defined as income/(loss) from vessel operations before general and administrative expenses, third-party debt modification fees and loss/(gain) on disposal of vessels and assets, net of impairments. The accounting policies followed by the reportable segments are the same as those followed in the preparation of the Company’s condensed consolidated financial statements. ​ Information about the Company’s reportable segments as of and for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Three months ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 132,411 ​ $ 154,719 ​ $ — ​ $ 287,130 Time charter equivalent revenues ​ ​ 129,285 ​ ​ 154,035 ​ ​ — ​ ​ 283,320 Depreciation and amortization ​ ​ 17,226 ​ ​ 12,294 ​ ​ 28 ​ ​ 29,548 Gain on disposal of vessels and other assets ​ ​ — ​ ​ (10,748) ​ ​ — ​ ​ (10,748) Adjusted income/(loss) from vessel operations ​ ​ 84,541 ​ ​ 101,690 ​ ​ (28) ​ ​ 186,203 Adjusted total assets at March 31, 2023 ​ ​ 1,455,356 ​ ​ 809,251 ​ ​ — ​ ​ 2,264,607 Expenditures for vessels and vessel improvements ​ ​ 65,728 ​ ​ 994 ​ ​ — ​ ​ 66,722 Payments for drydocking ​ ​ 2,128 ​ ​ 10,850 ​ ​ — ​ ​ 12,978 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 39,610 ​ $ 61,872 ​ $ — ​ $ 101,482 Time charter equivalent revenues ​ ​ 36,475 ​ ​ 61,500 ​ ​ — ​ ​ 97,975 Depreciation and amortization ​ ​ 15,152 ​ ​ 11,841 ​ ​ 7 ​ ​ 27,000 Loss/(gain) on disposal of vessels and other assets, net of impairments ​ ​ 1,843 ​ ​ (3,219) ​ ​ — ​ ​ (1,376) Adjusted (loss)/income from vessel operations ​ ​ (5,842) ​ ​ 9,198 ​ ​ (7) ​ ​ 3,349 Equity in results of affiliated companies ​ ​ 5,597 ​ ​ — ​ ​ — ​ ​ 5,597 Investments in and advances to affiliated companies at March 31, 2022 ​ ​ 160,298 ​ ​ 23,063 ​ ​ — ​ ​ 183,361 Adjusted total assets at March 31, 2022 ​ ​ 1,465,035 ​ ​ 803,077 ​ ​ — ​ ​ 2,268,112 Expenditures for vessels and vessel improvements ​ ​ 14,608 ​ ​ 23,381 ​ ​ — ​ ​ 37,989 Payments for drydocking ​ ​ 7,660 ​ ​ 9,910 ​ ​ — ​ ​ 17,570 ​ ​ Reconciliations of time charter equivalent (“TCE”) revenues of the segments to shipping revenues as reported in the condensed statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Time charter equivalent revenues ​ $ 283,320 ​ $ 97,975 Add: Voyage expenses ​ ​ 3,810 ​ ​ 3,507 Shipping revenues ​ $ 287,130 ​ $ 101,482 ​ Consistent with general practice in the shipping industry, the Company uses time charter equivalent revenues, which represent shipping revenues less voyage expenses, as a measure to compare revenue generated from a voyage charter to revenue generated from a time charter. Time charter equivalent revenues, a non-GAAP measure, provide additional meaningful information in conjunction with shipping revenues, the most directly comparable GAAP measure, because it assists Company management in making decisions regarding the deployment and use of its vessels and in evaluating their financial performance. ​ ​ Reconciliations of total adjusted income from vessel operations of the segments to income/(loss) before income taxes, as reported in the condensed consolidated statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Total adjusted income from vessel operations of all segments ​ $ 186,203 ​ $ 3,349 General and administrative expenses ​ ​ (11,246) ​ ​ (10,166) Third-party debt modification fees ​ ​ (407) ​ ​ (187) Gain on disposal of vessels and other assets, net of impairments ​ ​ 10,748 ​ ​ 1,376 Consolidated income/(loss) from vessel operations ​ ​ 185,298 ​ ​ (5,628) Equity in results of affiliated companies ​ ​ — ​ ​ 5,597 Other income/(expense) ​ ​ 4,281 ​ ​ (226) Interest expense ​ ​ (16,947) ​ ​ (12,740) Income/(loss) before income taxes ​ $ 172,632 ​ $ (12,997) ​ Reconciliations of total assets of the segments to amounts included in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ March 31, 2022 Adjusted total assets of all segments ​ $ 2,264,607 ​ $ 2,268,112 Corporate unrestricted cash and cash equivalents ​ ​ 156,220 ​ ​ 74,553 Restricted cash ​ ​ 18,329 ​ ​ 1,051 Short-term investments ​ ​ 105,000 ​ ​ — Other unallocated amounts ​ ​ 27,374 ​ ​ 22,877 Consolidated total assets ​ $ 2,571,530 ​ $ 2,366,593 ​

VESSELS

VESSELS	3 Months Ended
	Mar. 31, 2023
VESSELS [Abstract]
VESSELS	Note 5 — Vessels: ​ Impairment of Vessels and Other Property ​ During the three months ended March 31, 2023, the Company gave consideration as to whether events or changes in circumstances had occurred since December 31, 2022, that could indicate that the carrying amounts of the vessels in the Company’s fleet may not be recoverable. The Company determined that none of the vessels in the Company’s fleet met held-for-sale criteria as of March 31, 2023 and no held-for-use impairment indicators existed for the Company’s vessels as of March 31, 2023. The Company recognized a loss of approximately $0.2 million during the quarter ended March 31, 2023, related to the cost to terminate the purchase and installation contract for a ballast water treatment system on a vessel that was sold. ​ Vessel Acquisitions and Construction Commitments ​ On March 7, 2023, the first of Company’s three newbuild dual-fuel LNG VLCCs was delivered by the shipyard and shortly thereafter commenced its employment under a seven-year time charter contract with an oil major. The remaining commitments on the contracts for the construction of other two VLCCs as of March 31, 2023 was $115.2 million, which will be primarily funded by the BoComm Lease Financing (See Note 8, “Debt”) . ​ The second of the Company’s three newbuild dual-fuel LNG VLCC was delivered to the Company on April 11, 2023 and the third VLCC is expected to deliver before the end of the second quarter of 2023. ​ In December 2022 the Company tendered notice of its intention to exercise its options to purchase two 2009-built Aframaxes that it had been bareboat chartering-in. The aggregate purchase price for the two vessels was $43.0 million. On March 30, 2023, the Company completed the purchase of one of the two Aframaxes. The purchase of the second of the two vessels closed in early April 2023. ​ Disposal/Sales of Vessels ​ During the quarter ended March 31, 2023, the Company delivered a 2008-built MR to the buyer and recognized a gain of $10.9 million. ​

VARIABLE INTEREST ENTITIES (VIE

VARIABLE INTEREST ENTITIES (VIEs)	3 Months Ended
	Mar. 31, 2023
VARIABLE INTEREST ENTITIES (VIEs) [Abstract]
VARIABLE INTEREST ENTITIES (VIEs)	Note 6 — Variable Interest Entities (“VIEs”): ​ Unconsolidated VIEs ​ As of March 31, 2023, all of the six commercial pools in which the Company participates were determined to be VIEs for which the Company is not considered a primary beneficiary. ​ The following table presents the carrying amounts of assets and liabilities in the condensed consolidated balance sheet related to the unconsolidated VIEs as of March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ Condensed Pool working capital deposits ​ ​ ​ ​ $ 34,076 ​ In accordance with accounting guidance, the Company evaluated its maximum exposure to loss related to these unconsolidated VIEs by assuming a complete loss of the Company’s investment in these VIEs. The table below compares the Company’s liability in the condensed consolidated balance sheet to the maximum exposure to loss at March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Condensed ​ Maximum Exposure to Other Liabilities ​ $ – ​ $ 34,076 ​ In addition, as of March 31, 2023, the Company had approximately $236.6 million of trade receivables from the pools that were determined to be a VIE. These trade receivables, which are included in voyage receivables in the accompanying condensed consolidated balance sheet, have been excluded from the above tables and the calculation of INSW’s maximum exposure to loss. The Company does not record the maximum exposure to loss as a liability because it does not believe that such a loss is probable of occurring as of March 31, 2023.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES	3 Months Ended
	Mar. 31, 2023
FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES	​ Note 7 — Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures: ​ The estimated fair values of the Company’s financial instruments, other than derivatives that are not measured at fair value on a recurring basis, categorized based upon the fair value hierarchy, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 ​ Fair Value Level Cash and cash equivalents (1) ​ $ 174,549 ​ $ 243,744 ​ ​ Level 1 Short-term investments (2) ​ ​ 105,000 ​ ​ 80,000 ​ ​ Level 1 $750 Million Facility Term Loan (3) ​ ​ (356,637) ​ ​ (493,565) ​ ​ Level 2 ING Credit Facility (3) ​ ​ (22,396) ​ ​ (22,917) ​ ​ Level 2 Ocean Yield Lease Financing (3) ​ ​ (333,906) ​ ​ (341,106) ​ ​ Level 2 BoComm Lease Financing (4) ​ ​ (113,783) ​ ​ (63,598) ​ ​ Level 2 Toshin Lease Financing (4) ​ ​ (14,586) ​ ​ (14,744) ​ ​ Level 2 Hyuga Lease Financing (4) ​ ​ (14,585) ​ ​ (14,853) ​ ​ Level 2 COSCO Lease Financing (3) ​ ​ (46,479) ​ ​ (47,732) ​ ​ Level 2 Kaiyo Lease Financing (4) ​ ​ (13,414) ​ ​ (13,797) ​ ​ Level 2 Kaisha Lease Financing (4) ​ ​ (13,508) ​ ​ (13,704) ​ ​ Level 2 (1) Includes current restricted cash of $18.3 million at March 31, 2023. (2) Short-term investments consist of time deposits with original maturities of between 91 and 180 days. (3) Floating rate debt – the fair value of floating rate debt has been determined using level 2 inputs and is considered to be equal to the carrying value since it bears a variable interest rate, which is reset every three months. (4) Fixed rate debt – the fair value of fixed rate debt has been determined using level 2 inputs by discounting the expected cash flows of the outstanding debt. ​ Derivatives ​ In May 2022, in connection with the refinancing of its $390 Million Facility Term Loan and $525 Million Facility Term Loan, the Company terminated all of its existing in-the-money LIBOR based interest swaps with an aggregate notional amount of approximately $358.6 million and received net cash proceeds of approximately $9.6 million. As of March 31, 2023, approximately $3.8 million of the gain is expected to amortize out of accumulated other comprehensive income to earnings over the next 12 months. ​ Also, as of March 31, 2023, approximately $1.9 million of the loss with regards to the hybrid instrument associated with the Sinosure Credit Facility that was terminated in November 2021, is expected to amortize out of accumulated other comprehensive income to earnings over the next 12 months. ​ On June 2, 2022, the Company entered into amortizing interest rate swap agreements covering a notional amount of $475 million of the $750 Million Facility Term Loan with major financial institutions participating in such facility that effectively converts the Company’s interest rate exposure from a three-month SOFR floating rate to a fixed rate of 2.84% through the maturity date of February 22, 2027 , effective August 22, 2022. The interest rate swap agreements, which contain no leverage features, are designated and qualify as cash flow hedges. ​ ​ Derivatives are recorded on a net basis by counterparty when a legal right of offset exists. The Company had the following amounts recorded on a net basis by transaction in the accompanying unaudited condensed consolidated balance sheets related to the Company’s use of derivatives as of March 31, 2023 and December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Current portion of derivative asset ​ Long-term derivative ​ Current portion of derivative liabilities ​ Long-term derivative ​ Other March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 Total ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 Total ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 ​ The following tables present information with respect to gains and losses on derivative positions reflected in the condensed consolidated statements of operations or in the condensed consolidated statements of comprehensive income. ​ The effect of cash flow hedging relationships recognized in other comprehensive income/(loss) excluding amounts reclassified from accumulated other comprehensive income/(loss), including hedges of equity method investees, for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,454) ​ $ 9,058 Total other comprehensive (loss)/income ​ $ (1,454) ​ $ 9,058 ​ The effect of cash flow hedging relationships on the condensed consolidated statement of operations is presented excluding hedges of equity method investees. The effect of the Company’s cash flow hedging relationships on the condensed consolidated statement of operations for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,782) ​ $ 992 ​ ​ ​ ​ ​ ​ ​ Discontinued hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swap ​ ​ (602) ​ ​ 582 ​ ​ ​ ​ ​ ​ ​ Total interest expense ​ $ (2,384) ​ $ 1,574 ​ See Note 11, “Accumulated Other Comprehensive Income,” for disclosures relating to the impact of derivative instruments on accumulated other comprehensive income/(loss). ​ The following table presents the fair values, which are pre-tax, for assets and liabilities measured on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 ​ Fair Value Level Derivative Assets (interest rate swaps) ​ $ 9,180 ​ $ 12,196 ​ ​ Level 2 (1) (1) For the interest rate swaps, fair values are derived using valuation models that utilize the income valuation approach. These valuation models take into account contract terms such as maturity, as well as other inputs such as interest rate yield curves and creditworthiness of the counterparty and the Company.

DEBT

DEBT	3 Months Ended
	Mar. 31, 2023
DEBT [Abstract]
DEBT	Note 8 — Debt: ​ Debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 December 31, 2022 $750 Million Facility Term Loan, due 2027, net of unamortized deferred finance costs of $5,937 and $6,400 ​ $ 350,699 ​ $ 487,164 ING Credit Facility, due 2026, net of unamortized deferred finance costs of $385 and $416 ​ ​ 22,011 ​ ​ 22,501 Ocean Yield Lease Financing, due 2031, net of unamortized deferred finance costs of $3,061 and $3,198 ​ ​ 330,845 ​ ​ 337,908 BoComm Lease Financing, due 2030, net of unamortized deferred finance costs of $2,005 and $917 ​ ​ 126,786 ​ ​ 71,140 Toshin Lease Financing, due 2031, net of unamortized deferred finance costs of $354 and $370 ​ ​ 15,006 ​ ​ 15,215 COSCO Lease Financing, due 2028, net of unamortized deferred finance costs of $1,123 and $1,187 ​ ​ 45,355 ​ ​ 46,544 Hyuga Lease Financing, due 2031, net of unamortized deferred finance costs of $308 and $323 ​ ​ 14,774 ​ ​ 15,093 Kaiyo Lease Financing, due 2030, net of unamortized deferred finance costs of $270 and $285 ​ ​ 13,551 ​ ​ 13,884 Kaisha Lease Financing, due 2030, net of unamortized deferred finance costs of $282 and $298 ​ ​ 13,652 ​ ​ 13,983 ​ ​ ​ 932,679 ​ ​ 1,023,432 Less current portion ​ ​ (155,525) ​ ​ (162,854) Long-term portion ​ $ 777,154 ​ $ 860,578 ​ Capitalized terms used hereafter have the meaning given in these condensed consolidated financial statements or in the respective transaction documents referred to below, including subsequent amendments thereto. ​ $750 Million Credit Facility ​ On March 10, 2023, the Company entered into an amendment to the $750 Million Credit Facility. Pursuant to the amendment, the Company (a) prepaid $97 million of outstanding principal under the $750 Million Facility Term Loan; (b) obtained a release of collateral vessel mortgages over 22 MR product carriers; (c) received from the lenders additional revolving credit commitments in an aggregate amount of $40 million, which additional commitments constitute an increase to, and are subject to the same terms and conditions as, the previously-existing revolving credit commitments; and (d) made certain other amendments to the credit agreement and ancillary documents, including amendments relating to certain hedging obligations related to the credit agreement and to repayment schedules. Following the effectiveness of the amendment, (a) the aggregate outstanding principal amount under the ​ On March 14, 2023, the Company sold a 2008-built MR for approximately $20.2 million. The sale also resulted in a mandatory principal prepayment of approximately $9.7 million of the $750 Million Facility Term Loan and a $0.4 million further reduction in the scheduled future quarterly principal amortization. ​ ​ ​ BoComm Lease Financing Relating to Dual-Fuel LNG VLCC Newbuilds ​ On November 15, 2021, the Company and three of its vessel-owning indirect subsidiaries entered into a series of sale and leaseback arrangements with entities affiliated with the Bank of Communications Limited (“BoComm”) in connection with the construction of three dual-fuel LNG VLCC newbuilds (the “BoComm Lease Financing”). BoComm’s obligation to provide funding pursuant to the terms of the sale and leaseback agreements commenced when construction began on the first vessel in November 2021. The first and second of the three newbuilds were delivered to the Company on March 7, 2023 and April 11, 2023, respectively. The third is expected to be delivered prior to June 2023. The BoComm Lease Financing is expected to provide funding of $244.8 million in aggregate ( $81.6 million each vessel) over the course of the construction and delivery of the three vessels. ​ ​ Ocean Yield Lease Financing ​ The lease financing arrangements with Ocean Yield were amended on February 21, 2023, to change the reference rate from three-month LIBOR to an adjusted three-month Term SOFR rate, effective for the next interest rate reset date in May 2023. ​ ​ ING Credit Facility ​ The ING Credit Facility was amended on March 27, 2023, to change the reference rate from three-month LIBOR to an adjusted three-month Term SOFR rate, effective for the next interest rate reset date in May 2023. ​ ​ Debt Covenants ​ The Company was in compliance with the financial and non-financial covenants under all of its financing arrangements as of March 31, 2023. ​ ​ Interest Expense ​ Total interest expense before the impact of capitalized interest, including amortization of issuance and deferred financing costs (for additional information related to deferred financing costs see Note 2, “Significant Accounting Policies”), commitment, administrative and other fees for all of the Company’s debt facilities for the three months ended March 31, 2023 and 2022 was $18.4 million and $13.3 million, respectively ​ ​ Debt Modifications, Repurchases and Extinguishments ​ During the first quarter of 2023, the Company recognized a net loss of $0.2 million, which is included in other income/(expense) in the accompanying condensed consolidated statement of operations. The net loss reflects a write-off of unamortized deferred financing costs associated with the mandatory principal prepayment of the $750 Million Facility Term Loan in March 2023 in connection with the sale of a 2008-built MR (see Note 5, “Vessels”). ​

TAXES

TAXES	3 Months Ended
	Mar. 31, 2023
TAXES [Abstract]
TAXES	Note 9 — Taxes: ​ The Company derives substantially all of its gross income from the use and operation of vessels in international commerce. The Company’s entities that own and operate vessels are primarily domiciled in the Marshall Islands and Liberia, which do not impose income tax on shipping operations. The Company also has or had subsidiaries in various jurisdictions that perform administrative, commercial or technical management functions. These subsidiaries are subject to income tax based on the services performed in countries in which their offices are located; current and deferred income taxes are recorded accordingly. ​ A substantial portion of income earned by the Company is not subject to income tax. With respect to subsidiaries not subject to income tax in their respective countries of incorporation, no deferred taxes are provided for the temporary differences in the bases of the underlying assets and liabilities for tax and accounting purposes. ​ As of March 31, 2023, the Company believes it will qualify for an exemption from U.S. federal income taxes under Section 883 of the U.S. Internal Revenue Code of 1986, as amended (the “Code”) and U.S. Treasury Department regulations for the 2023 calendar year, so long as less than 50 percent of the total value of the Company’s stock is held by one or more shareholders who own 5% or more of the Company’s stock for more than half of the days of 2023. ​ The Company reviews its freight tax obligations on a regular basis and may update its assessment of its tax positions based on available information at that time. Such information may include additional legal advice as to the applicability of freight taxes in relevant jurisdictions. Freight tax regulations are subject to change and interpretation; therefore, the amounts recorded by the Company may change accordingly. ​ The Marshall Islands and Liberia impose tonnage taxes, which are assessed on the tonnage of certain of the Company’s vessels. These tonnage taxes are included in vessel expenses in the accompanying condensed consolidated statements of operations.

CAPITAL STOCK AND STOCK COMPENS

CAPITAL STOCK AND STOCK COMPENSATION	3 Months Ended
	Mar. 31, 2023
CAPITAL STOCK AND STOCK COMPENSATION [Abstract]
CAPITAL STOCK AND STOCK COMPENSATION	Note 10 — Capital Stock and Stock Compensation: ​ The Company accounts for stock-based compensation expense in accordance with the fair value method required by ASC 718, Compensation – Stock Compensation ​ Restricted Stock Units and Stock Option ​ In March 2023, the Company granted 52,890 time-based restricted stock units (“RSUs”) to certain of its senior officers and employees. The weighted average grant date fair value of these awards was $51.37 per RSU. Each RSU represents a contingent right to receive one share of INSW common stock upon vesting. All of the RSUs awarded will vest in equal installments on each of the first three anniversaries of the grant date. ​ In March 2023, the Company also awarded 52,890 performance-based RSUs to certain of its senior officers and employees. Each performance stock unit represents a contingent right to receive RSUs based upon the covered employees being continuously employed through the end of the period over which the performance goals are measured and shall vest as follows: (i) one ​ During the three months ended March 31, 2023, 12,940 stock options were exercised by certain senior officers and employees at an average exercise price of $22.54 per share. After withholdings for taxes and exercise costs, the Company issued a total of 3,319 shares in conjunction with these transactions. ​ Dividends ​ During the first quarter of 2023, the Company’s Board of Directors declared a regular quarterly cash dividend of $0.12 per share of common stock and a supplemental cash dividend of $1.88 per share of common stock. Pursuant to such dividend declarations, the Company made dividend payments totaling $98.3 million during the quarter ended March 31, 2023. On ​ Share Repurchases ​ No shares were acquired under the Company’s stock repurchase program during the three months ended March 31, 2023 and 2022. As of March 31, 2023, the remaining buyback authorization under the Company’s was $40.0 million. ​ In connection with the settlement of vested restricted stock units and the exercise of stock options, the Company repurchased 59,292 and 57,726 shares of common stock during the three months ended March 31, 2023 and 2022, respectively, at an average cost of $55.16 and $16.81, respectively, per share (based on the market prices on the dates of vesting or exercise) from employees and certain members of management to cover withholding taxes. ​ Rights Agreement ​ On April 11, 2023, the Company’s Board of Directors approved the Amended and Restated the Rights Agreement (the “A&R Rights Agreement”), which amends and restates the Original Rights Agreement dated as of May 8, 2022. The A&R Rights Agreement implements substantially the same features and protective measures of the Original Rights Agreements and includes the following revised or additional provisions: (i) extends the expiration date from May 7, 2023 to April 10, 2026; (ii) increases the “Acquiring Person” trigger threshold from 17.5% to 20% ; (iii) increases the “Purchase Price” from $25 to $50 ; and (iv) includes a qualifying offer provision with a shareholder redemption feature. ​ The Company’s Board of Directors adopted the Original Rights Agreement and the A&R Rights Agreement to enable all stockholders of the Company to realize the full potential value of their investment in the Company. The A&R Rights Agreement is designed to prevent any individual stockholder or group of stockholders from gaining control of the Company through open market accumulation without paying a control premium to all stockholders or by otherwise disadvantaging other stockholders. The A&R Rights Agreement is not intended to prevent a takeover or deter fair offers for securities of the Company that deliver value to all stockholders on an equal basis. It is designed, instead, to encourage anyone seeking to acquire the Company to negotiate with the Board prior to attempting a takeover. ​ The Company’s Board of Directors may consider an earlier termination of the A&R Rights Agreement if market and other conditions warrant. ​ ​ ​

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME	3 Months Ended
	Mar. 31, 2023
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME	Note 11 — Accumulated Other Comprehensive Income: ​ The components of accumulated other comprehensive income/(loss), net of related taxes, in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 December 31, 2022 Unrealized gains on derivative instruments ​ $ 13,074 ​ $ 16,912 Items not yet recognized as a component of net periodic benefit cost (pension plans) ​ ​ (10,172) ​ ​ (9,948) ​ ​ $ 2,902 ​ $ 6,964 ​ ​ The changes in the balances of each component of accumulated other comprehensive income/(loss), net of related taxes, during the three months ended March 31, 2023 and 2022 follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Unrealized gains/(losses) on cash flow hedges ​ Items not yet recognized as a component of net periodic benefit cost ​ Total Balance as of December 31, 2022 ​ $ 16,912 ​ $ (9,948) ​ $ 6,964 Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive income ​ ​ (1,454) ​ ​ (224) ​ ​ (1,678) Amounts reclassified from accumulated other comprehensive income ​ ​ (2,384) ​ ​ — ​ ​ (2,384) Balance as of March 31, 2023 ​ $ 13,074 ​ $ (10,172) ​ $ 2,902 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ (4,863) ​ ​ (7,497) ​ ​ (12,360) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 9,058 ​ ​ 197 ​ ​ 9,255 Amounts reclassified from accumulated other comprehensive loss ​ ​ 1,704 ​ ​ — ​ ​ 1,704 Balance as of March 31, 2022 ​ $ 5,899 ​ $ (7,300) ​ $ (1,401) ​ ​ ​ ​ Amounts reclassified out of each component of accumulated other comprehensive income/(loss) follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ Statement of Operations Reclassifications of (gains)/losses on cash flow hedges: ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps entered into by the Company's ​ ​ ​ ​ ​ ​ ​ Equity in results of equity method joint venture investees ​ $ — ​ $ 130 ​ affiliated companies Interest rate swaps entered into by the Company's subsidiaries ​ ​ (1,782) ​ ​ 992 ​ Interest expense ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassifications of losses on discontinued hedging instruments ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap entered into by the Company's subsidiaries ​ ​ (602) ​ ​ 582 ​ Interest expense Total before and net of tax ​ $ (2,384) ​ $ 1,704 ​ ​ ​ At March 31, 2023, the Company expects that it will reclassify $6.6 million (gross and net of tax) of net gain on derivative instruments from accumulated other comprehensive income to earnings during the next twelve months attributable to interest rate swaps held by the Company. ​ See Note 7, “Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures,” for additional disclosures relating to derivative instruments.

REVENUE

REVENUE	3 Months Ended
	Mar. 31, 2023
REVENUE [Abstract]
REVENUE	Note 12 — Revenue: ​ Revenue Recognition ​ The majority of the Company's contracts for pool revenues, time charter revenues, and voyage charter revenues are accounted for as lease revenue under ASC 842. The Company's contracts with pools are short term which are cancellable with up to 90 days' notice. As of March 31, 2023, the Company is a party to time charter out contracts with customers on two VLCCs, two Suezmaxes, one LR2 and three MRs, with expiry dates ranging from May 2023 to February 2030. The Company's contracts with customers for voyage charters are short term and vary in length based upon the duration of each voyage. Lease revenue for non-variable lease payments is recognized over the lease term on a straight-line basis and lease revenue for variable lease payments (e.g., demurrage) is recognized in the period in which the changes in facts and circumstances on which the variable lease payments are based occur. ​ Lightering services provided by the Company's Crude Tanker Lightering Business, and voyage charter contracts that do not meet the definition of a lease are accounted for as service revenues under ASC 606. In accordance with ASC 606, revenue is recognized when a customer obtains control of or consumes promised services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these services. ​ The following table presents the Company’s revenues from leases accounted for under ASC 842 and revenues from services accounted for under ASC 606 for the three months ended March 31, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Three months ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 108,799 ​ $ 150,779 ​ $ 259,578 Time charter revenues ​ ​ 9,686 ​ ​ 3,464 ​ ​ 13,150 Voyage charter revenues from non-variable lease payments ​ ​ 2,238 ​ ​ 326 ​ ​ 2,564 Voyage charter revenues from variable lease payments ​ ​ — ​ ​ 150 ​ ​ 150 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 11,688 ​ ​ — ​ ​ 11,688 Total shipping revenues ​ $ 132,411 ​ $ 154,719 ​ $ 287,130 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 27,310 ​ $ 56,452 ​ $ 83,762 Time charter revenues ​ ​ 3,724 ​ ​ 2,451 ​ ​ 6,175 Voyage charter revenues from non-variable lease payments ​ ​ 2,844 ​ ​ 3,047 ​ ​ 5,891 Voyage charter revenues from variable lease payments ​ ​ 14 ​ ​ (78) ​ ​ (64) Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 5,718 ​ ​ — ​ ​ 5,718 Total shipping revenues ​ $ 39,610 ​ $ 61,872 ​ $ 101,482 ​ Contract Balances ​ The following table provides information about receivables, contract assets and contract liabilities from contracts with customers, and significant changes in contract assets and liabilities balances, associated with revenue from services accounted for under ASC 606. Balances related to revenues from leases accounted for under ASC 842 are excluded from the table below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Voyage receivables - Billed receivables ​ Contract assets (Unbilled voyage receivables) ​ Contract liabilities (Deferred revenues and off hires) Opening balance as of January 1, 2023 ​ $ 9,452 ​ $ 1,866 ​ $ — Closing balance as of March 31, 2023 ​ ​ 6,116 ​ ​ 208 ​ ​ — ​ We receive payments from customers based on the schedule established in our contracts. Contract assets relate to our conditional right to consideration for our completed performance obligations under contracts and decrease when the right to consideration becomes unconditional or payments are received. Contract liabilities include payments received in advance of performance under contracts and are recognized when performance under the respective contract has been completed. Deferred revenues allocated to unsatisfied performance obligations will be recognized over time as the services are performed. ​ Performance Obligations ​ All of the Company’s performance obligations are generally transferred to customers over time. The expected duration of services is less than one year. There were no material adjustments in revenues from performance obligations satisfied in previous periods recognized during the three months ended March 31, 2023 and 2022, respectively. ​ Costs to Obtain or Fulfill a Contract As of March 31, 2023, there were no unamortized deferred costs of obtaining or fulfilling a contract.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2023
LEASES [Abstract]
LEASES	​ Note 13 — Leases: ​ As permitted under ASC 842, the Company has elected not to apply the provisions of ASC 842 to short term leases, which include: (i) tanker vessels chartered-in where the duration of the charter was one year or less at inception; (ii) workboats employed in the Crude Tankers Lightering business which have a lease term of 12-months or less; and (iii) short term leases of office and other space. ​ Contracts under which the Company is a Lessee ​ The Company currently has two major categories of leases - chartered-in vessels and leased office and other space. The expenses recognized during the three months ended March 31, 2023 and 2022 for the lease component of these leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Operating lease cost ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ Charter hire expenses ​ $ 1,067 ​ $ 2,418 ​ ​ ​ ​ ​ ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ 715 ​ ​ — Interest on lease liabilities ​ ​ 121 ​ ​ — ​ ​ ​ ​ ​ ​ ​ Office and other space ​ ​ ​ ​ ​ ​ General and administrative ​ ​ 228 ​ ​ 227 Voyage expenses ​ ​ 45 ​ ​ 43 ​ ​ ​ ​ ​ ​ ​ Short-term lease cost ​ ​ ​ ​ ​ ​ Vessel assets (1) ​ ​ ​ ​ ​ ​ Charter hire expenses ​ ​ 4,269 ​ ​ 1,479 Total lease cost ​ $ 6,445 ​ $ 4,167 (1) Excludes vessels spot chartered-in under operating leases and employed in the Crude Tankers Lightering business for periods of less than one month each, totaling $0.1 million and $0.4 million for the three months ended March 31, 2023 and 2022, respectively, including both lease and non-lease components. ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows used for operating leases ​ $ 937 ​ $ 2,486 Finance cash flows used for finance leases ​ ​ 23,955 ​ ​ — ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 Operating lease right-of-use assets ​ $ 7,085 ​ $ 8,471 Finance lease right-of-use assets ​ ​ 22,001 ​ ​ 44,391 ​ ​ ​ ​ ​ ​ ​ Current portion of operating lease liabilities ​ $ (430) ​ $ (1,596) Current portion of finance lease liabilities ​ ​ (18,326) ​ ​ (41,870) Long-term operating lease liabilities ​ ​ (7,738) ​ ​ (7,740) Total operating and finance lease liabilities ​ $ (26,494) ​ $ (51,206) ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term - operating leases (1) ​ ​ 9.59 years ​ ​ 8.56 years Weighted average discount rate - operating leases (1) ​ ​ 4.37% ​ ​ 4.13% ​ (1) The weighted average remaining lease term and discount rate as of March 31, 2023 and December 31, 2022 exclude finance lease liabilities. Such finance leases had weighted average remaining lease terms of 0.01 years and 0.20 years at March 31, 2023 and December 31, 2022, respectively, and the annualized weighted average discount rate was 4.78% as of March 31, 2023 and December 31, 2022. 1. Charters-in of vessel assets: ​ As of March 31, 2023, INSW had commitments to charter in one Aframax and two LR1s. The LR1s, which are time charters, with expiry dates in April 2023, are accounted for as operating leases. The Aframax is a bareboat charter that was accounted for as an operating lease up until December 6, 2022, when the Company declared its option to purchase the Aframax. The purchase of the Aframax closed in early April 2023. ​ Payments of lease liabilities and related number of operating days under these operating and finance leases as of March 31, 2023 are as follows: ​ Bareboat Charters-in: ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Operating Days 2023 ​ $ 18,329 ​ 4 Total lease payments, including vessel purchase price ​ ​ 18,329 ​ 4 less imputed interest ​ ​ (3) ​ ​ Total finance lease liabilities ​ $ 18,326 ​ ​ ​ Time Charters-in: ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Operating Days 2023 ​ $ 192 ​ 30 ​ ​ ​ ​ ​ ​ Total lease payments (lease component only) ​ ​ 192 ​ 30 less imputed interest ​ ​ — ​ ​ Total operating lease liabilities ​ $ 192 ​ ​ ​ 2. Office and other space: ​ The Company has operating leases for offices and lightering workboat dock space. These leases have expiry dates ranging from July 2023 to May 2033. The lease for the workboat dock space contains renewal options executable by the Company for periods through December 2027. We have determined that the options through December 2024 are reasonably certain to be executed by the Company, and accordingly the options are included in the lease liability and right of use asset calculations for such lease. ​ Payments of lease liabilities for office and other space as of March 31, 2023 are as follows: ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Amount 2023 ​ $ 159 2024 ​ ​ 973 2025 ​ ​ 998 2026 ​ ​ 1,024 2027 ​ ​ 1,077 Thereafter ​ ​ 5,831 Total lease payments ​ ​ 10,062 less imputed interest ​ ​ (2,086) Total operating lease liabilities ​ $ 7,976 ​ Contracts under which the Company is a Lessor ​ See Note 12, “Revenue,” for discussion on the Company’s revenues from operating leases accounted for under ASC 842. ​ The future minimum revenues, before reduction for brokerage commissions, expected to be received on non-cancelable time charters for two VLCCs, two Suezmaxes, one LR2 and three MRs, and the related revenue days as of March 31, 2023 are as follows: ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Revenue Days 2023 ​ $ 46,606 ​ 1,709 2024 ​ ​ 45,948 ​ 1,688 2025 ​ ​ 13,484 ​ 462 2026 ​ ​ 11,315 ​ 365 2027 ​ ​ 11,315 ​ 365 Thereafter ​ ​ 23,870 ​ 770 Future minimum revenues ​ $ 152,537 ​ 5,359 ​ Future minimum revenues do not include the Company’s share of time charters entered into by the pools in which it participates or profit-sharing above the base rate on the newbuild dual-fuel LNG VLCCs. Revenues from a time charter are not generally received when a vessel is off-hire, including time required for normal periodic maintenance of the vessel. In arriving at the minimum future charter revenues, an estimated time off-hire to perform periodic maintenance on each vessel has been deducted, although there is no assurance that such estimate will be reflective of the actual off-hire in the future. ​ Upon their delivery during the second quarter of 2023, the remaining two of the Company’s three newbuild dual-fuel LNG VLCCs will each commence employment under seven-year time charter contracts with an oil major.

CONTINGENCIES

CONTINGENCIES	3 Months Ended
	Mar. 31, 2023
CONTINGENCIES [Abstract]
CONTINGENCIES	Note 14 — Contingencies: ​ INSW’s policy for recording legal costs related to contingencies is to expense such legal costs as incurred. ​ Multi-Employer Plans ​ The Merchant Navy Officers Pension Fund (“MNOPF”) is a multi-employer defined benefit pension plan covering British crew members that served as officers on board INSW’s vessels (as well as vessels of other owners). The trustees of the plan have indicated that, under the terms of the High Court ruling in 2005, which established the liability of past employers to fund the deficit on the Post 1978 section of MNOPF, calls for further contributions may be required if additional actuarial deficits arise or if other employers liable for contributions are not able to pay their share in the future. As the amount of any such assessment cannot be reasonably estimated, no reserves have been recorded for this contingency in INSW’s consolidated financial statements as of March 31, 2023. The MNOPF annual actuarial report as of March 31, 2022, showed the pension scheme funded status as being in surplus and no additional employer contributions were due. The next full actuarial valuation will be as of March 31, 2024. ​ ​ The Merchant Navy Ratings Pension Fund (“MNRPF”) is a multi-employer defined benefit pension plan covering British crew members that served as ratings (seamen) on board INSW’s vessels (as well as vessels of other owners) more than 20 years ago. Participating employers include current employers, historic employers that have made voluntary contributions, and historic employers such as INSW that have made no deficit contributions. Calls for contributions may be required if additional actuarial deficits arise or if other employers liable for contributions are unable to pay their share in the future. As the amount of any such assessment cannot be reasonably estimated, no reserves have been recorded in INSW’s consolidated financial statements as of March 31, 2023. The deficit valuation as of March 31, 2023 is expected to be finalized by June 30, 2024. ​ ​ ​ ​ Spin-Off Related Agreements On November 30, 2016, INSW was spun off from OSG as a separate publicly traded company. In connection with the spin-off, INSW and OSG entered into several agreements, including a separation and distribution agreement, an employee matters agreement and a transition services agreement. While most of the obligations under those agreements were subsequently fulfilled, certain provisions (including in particular mutual indemnification provisions under the separation and distribution agreement and the employee matters agreement) continue in force. ​ Legal Proceedings Arising in the Ordinary Course of Business ​ The Company is a party, as plaintiff or defendant, to various suits in the ordinary course of business for monetary relief arising principally from personal injuries, wrongful death, collision or other casualty and to claims arising under charter parties and other contract disputes. A substantial majority of such personal injury, wrongful death, collision or other casualty claims against the Company are covered by insurance (subject to deductibles not material in amount). Each of the claims involves an amount which, in the opinion of management, should not be material to the Company’s financial position, results of operations and cash flows.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Cash, cash equivalents and restricted cash	Cash, cash equivalents and restricted cash —
Short-term investments	Short-term investments
Concentration of Credit Risk	​ Concentration of Credit Risk — ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Allowance for Credit Losses - Balance at December 31, 2022 ​ $ 261 Reversal of expected credit losses ​ ​ (138) Balance at March 31, 2023 ​ $ 123 ​ During the three months ended March 31, 2023 and 2022, the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted in aggregate for 96% of consolidated voyage receivables at both March 31, 2023 and December 31, 2022, respectively.
Deferred finance charges	Deferred finance charges — ​ Interest expense relating to the amortization of deferred financing charges amounted to $1.3 million and $0.6 million for the three months ended March 31, 2023 and 2022, respectively.
Vessels construction in progress	Vessels construction in progress — ​
Recently adopted / issued accounting standards	Recently Issued Accounting Standards

CONTINGENCIES (Policy)

CONTINGENCIES (Policy)	3 Months Ended
	Mar. 31, 2023
CONTINGENCIES [Abstract]
Legal costs	​ INSW’s policy for recording legal costs related to contingencies is to expense such legal costs as incurred.

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	3 Months Ended
	Mar. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Activity for allowance for credit losses	​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Allowance for Credit Losses - Balance at December 31, 2022 ​ $ 261 Reversal of expected credit losses ​ ​ (138) Balance at March 31, 2023 ​ $ 123 ​

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	3 Months Ended
	Mar. 31, 2023
EARNINGS PER COMMON SHARE [Abstract]
Components of Calculation of Earnings Per Share	​ ​ ​ Reconciliations of the numerator of the basic and diluted earnings per share computations are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Net income/(loss) allocated to: ​ ​ ​ ​ ​ ​ Common Stockholders ​ $ 172,466 ​ $ (13,006) Participating securities ​ ​ 167 ​ ​ 5 ​ ​ $ 172,633 ​ $ (13,001) ​

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING (Tables)	3 Months Ended
	Mar. 31, 2023
BUSINESS AND SEGMENT REPORTING [Abstract]
Schedule of Segment Reporting Information, by Segment	​ Information about the Company’s reportable segments as of and for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Three months ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 132,411 ​ $ 154,719 ​ $ — ​ $ 287,130 Time charter equivalent revenues ​ ​ 129,285 ​ ​ 154,035 ​ ​ — ​ ​ 283,320 Depreciation and amortization ​ ​ 17,226 ​ ​ 12,294 ​ ​ 28 ​ ​ 29,548 Gain on disposal of vessels and other assets ​ ​ — ​ ​ (10,748) ​ ​ — ​ ​ (10,748) Adjusted income/(loss) from vessel operations ​ ​ 84,541 ​ ​ 101,690 ​ ​ (28) ​ ​ 186,203 Adjusted total assets at March 31, 2023 ​ ​ 1,455,356 ​ ​ 809,251 ​ ​ — ​ ​ 2,264,607 Expenditures for vessels and vessel improvements ​ ​ 65,728 ​ ​ 994 ​ ​ — ​ ​ 66,722 Payments for drydocking ​ ​ 2,128 ​ ​ 10,850 ​ ​ — ​ ​ 12,978 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 39,610 ​ $ 61,872 ​ $ — ​ $ 101,482 Time charter equivalent revenues ​ ​ 36,475 ​ ​ 61,500 ​ ​ — ​ ​ 97,975 Depreciation and amortization ​ ​ 15,152 ​ ​ 11,841 ​ ​ 7 ​ ​ 27,000 Loss/(gain) on disposal of vessels and other assets, net of impairments ​ ​ 1,843 ​ ​ (3,219) ​ ​ — ​ ​ (1,376) Adjusted (loss)/income from vessel operations ​ ​ (5,842) ​ ​ 9,198 ​ ​ (7) ​ ​ 3,349 Equity in results of affiliated companies ​ ​ 5,597 ​ ​ — ​ ​ — ​ ​ 5,597 Investments in and advances to affiliated companies at March 31, 2022 ​ ​ 160,298 ​ ​ 23,063 ​ ​ — ​ ​ 183,361 Adjusted total assets at March 31, 2022 ​ ​ 1,465,035 ​ ​ 803,077 ​ ​ — ​ ​ 2,268,112 Expenditures for vessels and vessel improvements ​ ​ 14,608 ​ ​ 23,381 ​ ​ — ​ ​ 37,989 Payments for drydocking ​ ​ 7,660 ​ ​ 9,910 ​ ​ — ​ ​ 17,570 ​ ​
Reconciliation of Revenue from Segments to Consolidated	Reconciliations of time charter equivalent (“TCE”) revenues of the segments to shipping revenues as reported in the condensed statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Time charter equivalent revenues ​ $ 283,320 ​ $ 97,975 Add: Voyage expenses ​ ​ 3,810 ​ ​ 3,507 Shipping revenues ​ $ 287,130 ​ $ 101,482 ​
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	​ Reconciliations of total adjusted income from vessel operations of the segments to income/(loss) before income taxes, as reported in the condensed consolidated statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Total adjusted income from vessel operations of all segments ​ $ 186,203 ​ $ 3,349 General and administrative expenses ​ ​ (11,246) ​ ​ (10,166) Third-party debt modification fees ​ ​ (407) ​ ​ (187) Gain on disposal of vessels and other assets, net of impairments ​ ​ 10,748 ​ ​ 1,376 Consolidated income/(loss) from vessel operations ​ ​ 185,298 ​ ​ (5,628) Equity in results of affiliated companies ​ ​ — ​ ​ 5,597 Other income/(expense) ​ ​ 4,281 ​ ​ (226) Interest expense ​ ​ (16,947) ​ ​ (12,740) Income/(loss) before income taxes ​ $ 172,632 ​ $ (12,997) ​
Reconciliation of Assets from Segment to Consolidated	Reconciliations of total assets of the segments to amounts included in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ March 31, 2022 Adjusted total assets of all segments ​ $ 2,264,607 ​ $ 2,268,112 Corporate unrestricted cash and cash equivalents ​ ​ 156,220 ​ ​ 74,553 Restricted cash ​ ​ 18,329 ​ ​ 1,051 Short-term investments ​ ​ 105,000 ​ ​ — Other unallocated amounts ​ ​ 27,374 ​ ​ 22,877 Consolidated total assets ​ $ 2,571,530 ​ $ 2,366,593

VARIABLE INTEREST ENTITIES (V_2

VARIABLE INTEREST ENTITIES (VIEs) (Tables)	3 Months Ended
	Mar. 31, 2023
VARIABLE INTEREST ENTITIES (VIEs) [Abstract]
Schedule of Variable Interest Entities	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ Condensed Pool working capital deposits ​ ​ ​ ​ $ 34,076 ​
Schedule of Variable Interest Entities Liability in Condensed Consolidated Balance Sheet to Maximum Exposure to Loss	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Condensed ​ Maximum Exposure to Other Liabilities ​ $ – ​ $ 34,076 ​

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Tables)	3 Months Ended
	Mar. 31, 2023
FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES [Abstract]
Fair Value, by Balance Sheet Grouping	The estimated fair values of the Company’s financial instruments, other than derivatives that are not measured at fair value on a recurring basis, categorized based upon the fair value hierarchy, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 ​ Fair Value Level Cash and cash equivalents (1) ​ $ 174,549 ​ $ 243,744 ​ ​ Level 1 Short-term investments (2) ​ ​ 105,000 ​ ​ 80,000 ​ ​ Level 1 $750 Million Facility Term Loan (3) ​ ​ (356,637) ​ ​ (493,565) ​ ​ Level 2 ING Credit Facility (3) ​ ​ (22,396) ​ ​ (22,917) ​ ​ Level 2 Ocean Yield Lease Financing (3) ​ ​ (333,906) ​ ​ (341,106) ​ ​ Level 2 BoComm Lease Financing (4) ​ ​ (113,783) ​ ​ (63,598) ​ ​ Level 2 Toshin Lease Financing (4) ​ ​ (14,586) ​ ​ (14,744) ​ ​ Level 2 Hyuga Lease Financing (4) ​ ​ (14,585) ​ ​ (14,853) ​ ​ Level 2 COSCO Lease Financing (3) ​ ​ (46,479) ​ ​ (47,732) ​ ​ Level 2 Kaiyo Lease Financing (4) ​ ​ (13,414) ​ ​ (13,797) ​ ​ Level 2 Kaisha Lease Financing (4) ​ ​ (13,508) ​ ​ (13,704) ​ ​ Level 2 (1) Includes current restricted cash of $18.3 million at March 31, 2023. (2) Short-term investments consist of time deposits with original maturities of between 91 and 180 days. (3) Floating rate debt – the fair value of floating rate debt has been determined using level 2 inputs and is considered to be equal to the carrying value since it bears a variable interest rate, which is reset every three months. (4) Fixed rate debt – the fair value of fixed rate debt has been determined using level 2 inputs by discounting the expected cash flows of the outstanding debt.
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Current portion of derivative asset ​ Long-term derivative ​ Current portion of derivative liabilities ​ Long-term derivative ​ Other March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 Total ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 Total ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 ​
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Loss	The effect of cash flow hedging relationships recognized in other comprehensive income/(loss) excluding amounts reclassified from accumulated other comprehensive income/(loss), including hedges of equity method investees, for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,454) ​ $ 9,058 Total other comprehensive (loss)/income ​ $ (1,454) ​ $ 9,058 ​ The effect of cash flow hedging relationships on the condensed consolidated statement of operations is presented excluding hedges of equity method investees. The effect of the Company’s cash flow hedging relationships on the condensed consolidated statement of operations for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,782) ​ $ 992 ​ ​ ​ ​ ​ ​ ​ Discontinued hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swap ​ ​ (602) ​ ​ 582 ​ ​ ​ ​ ​ ​ ​ Total interest expense ​ $ (2,384) ​ $ 1,574 ​
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	​ Note 7 — Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures: ​ The estimated fair values of the Company’s financial instruments, other than derivatives that are not measured at fair value on a recurring basis, categorized based upon the fair value hierarchy, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 ​ Fair Value Level Cash and cash equivalents (1) ​ $ 174,549 ​ $ 243,744 ​ ​ Level 1 Short-term investments (2) ​ ​ 105,000 ​ ​ 80,000 ​ ​ Level 1 $750 Million Facility Term Loan (3) ​ ​ (356,637) ​ ​ (493,565) ​ ​ Level 2 ING Credit Facility (3) ​ ​ (22,396) ​ ​ (22,917) ​ ​ Level 2 Ocean Yield Lease Financing (3) ​ ​ (333,906) ​ ​ (341,106) ​ ​ Level 2 BoComm Lease Financing (4) ​ ​ (113,783) ​ ​ (63,598) ​ ​ Level 2 Toshin Lease Financing (4) ​ ​ (14,586) ​ ​ (14,744) ​ ​ Level 2 Hyuga Lease Financing (4) ​ ​ (14,585) ​ ​ (14,853) ​ ​ Level 2 COSCO Lease Financing (3) ​ ​ (46,479) ​ ​ (47,732) ​ ​ Level 2 Kaiyo Lease Financing (4) ​ ​ (13,414) ​ ​ (13,797) ​ ​ Level 2 Kaisha Lease Financing (4) ​ ​ (13,508) ​ ​ (13,704) ​ ​ Level 2 (1) Includes current restricted cash of $18.3 million at March 31, 2023. (2) Short-term investments consist of time deposits with original maturities of between 91 and 180 days. (3) Floating rate debt – the fair value of floating rate debt has been determined using level 2 inputs and is considered to be equal to the carrying value since it bears a variable interest rate, which is reset every three months. (4) Fixed rate debt – the fair value of fixed rate debt has been determined using level 2 inputs by discounting the expected cash flows of the outstanding debt. ​ Derivatives ​ In May 2022, in connection with the refinancing of its $390 Million Facility Term Loan and $525 Million Facility Term Loan, the Company terminated all of its existing in-the-money LIBOR based interest swaps with an aggregate notional amount of approximately $358.6 million and received net cash proceeds of approximately $9.6 million. As of March 31, 2023, approximately $3.8 million of the gain is expected to amortize out of accumulated other comprehensive income to earnings over the next 12 months. ​ Also, as of March 31, 2023, approximately $1.9 million of the loss with regards to the hybrid instrument associated with the Sinosure Credit Facility that was terminated in November 2021, is expected to amortize out of accumulated other comprehensive income to earnings over the next 12 months. ​ On June 2, 2022, the Company entered into amortizing interest rate swap agreements covering a notional amount of $475 million of the $750 Million Facility Term Loan with major financial institutions participating in such facility that effectively converts the Company’s interest rate exposure from a three-month SOFR floating rate to a fixed rate of 2.84% through the maturity date of February 22, 2027 , effective August 22, 2022. The interest rate swap agreements, which contain no leverage features, are designated and qualify as cash flow hedges. ​ ​ Derivatives are recorded on a net basis by counterparty when a legal right of offset exists. The Company had the following amounts recorded on a net basis by transaction in the accompanying unaudited condensed consolidated balance sheets related to the Company’s use of derivatives as of March 31, 2023 and December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Current portion of derivative asset ​ Long-term derivative ​ Current portion of derivative liabilities ​ Long-term derivative ​ Other March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 Total ​ $ 6,274 ​ $ 2,138 ​ $ — ​ $ — ​ $ 768 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 Total ​ $ 6,987 ​ $ 4,662 ​ $ — ​ $ — ​ $ 547 ​ The following tables present information with respect to gains and losses on derivative positions reflected in the condensed consolidated statements of operations or in the condensed consolidated statements of comprehensive income. ​ The effect of cash flow hedging relationships recognized in other comprehensive income/(loss) excluding amounts reclassified from accumulated other comprehensive income/(loss), including hedges of equity method investees, for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,454) ​ $ 9,058 Total other comprehensive (loss)/income ​ $ (1,454) ​ $ 9,058 ​ The effect of cash flow hedging relationships on the condensed consolidated statement of operations is presented excluding hedges of equity method investees. The effect of the Company’s cash flow hedging relationships on the condensed consolidated statement of operations for the three months ended March 31, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (1,782) ​ $ 992 ​ ​ ​ ​ ​ ​ ​ Discontinued hedging instruments: ​ ​ ​ ​ ​ ​ Interest rate swap ​ ​ (602) ​ ​ 582 ​ ​ ​ ​ ​ ​ ​ Total interest expense ​ $ (2,384) ​ $ 1,574 ​ See Note 11, “Accumulated Other Comprehensive Income,” for disclosures relating to the impact of derivative instruments on accumulated other comprehensive income/(loss). ​ The following table presents the fair values, which are pre-tax, for assets and liabilities measured on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 ​ Fair Value Level Derivative Assets (interest rate swaps) ​ $ 9,180 ​ $ 12,196 ​ ​ Level 2 (1) (1) For the interest rate swaps, fair values are derived using valuation models that utilize the income valuation approach. These valuation models take into account contract terms such as maturity, as well as other inputs such as interest rate yield curves and creditworthiness of the counterparty and the Company.

DEBT (Tables)

DEBT (Tables)	3 Months Ended
	Mar. 31, 2023
DEBT [Abstract]
Schedule of Long-term Debt Instruments	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 December 31, 2022 $750 Million Facility Term Loan, due 2027, net of unamortized deferred finance costs of $5,937 and $6,400 ​ $ 350,699 ​ $ 487,164 ING Credit Facility, due 2026, net of unamortized deferred finance costs of $385 and $416 ​ ​ 22,011 ​ ​ 22,501 Ocean Yield Lease Financing, due 2031, net of unamortized deferred finance costs of $3,061 and $3,198 ​ ​ 330,845 ​ ​ 337,908 BoComm Lease Financing, due 2030, net of unamortized deferred finance costs of $2,005 and $917 ​ ​ 126,786 ​ ​ 71,140 Toshin Lease Financing, due 2031, net of unamortized deferred finance costs of $354 and $370 ​ ​ 15,006 ​ ​ 15,215 COSCO Lease Financing, due 2028, net of unamortized deferred finance costs of $1,123 and $1,187 ​ ​ 45,355 ​ ​ 46,544 Hyuga Lease Financing, due 2031, net of unamortized deferred finance costs of $308 and $323 ​ ​ 14,774 ​ ​ 15,093 Kaiyo Lease Financing, due 2030, net of unamortized deferred finance costs of $270 and $285 ​ ​ 13,551 ​ ​ 13,884 Kaisha Lease Financing, due 2030, net of unamortized deferred finance costs of $282 and $298 ​ ​ 13,652 ​ ​ 13,983 ​ ​ ​ 932,679 ​ ​ 1,023,432 Less current portion ​ ​ (155,525) ​ ​ (162,854) Long-term portion ​ $ 777,154 ​ $ 860,578 ​

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	3 Months Ended
	Mar. 31, 2023
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive income/(loss), net of related taxes, in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 December 31, 2022 Unrealized gains on derivative instruments ​ $ 13,074 ​ $ 16,912 Items not yet recognized as a component of net periodic benefit cost (pension plans) ​ ​ (10,172) ​ ​ (9,948) ​ ​ $ 2,902 ​ $ 6,964 ​ ​ The changes in the balances of each component of accumulated other comprehensive income/(loss), net of related taxes, during the three months ended March 31, 2023 and 2022 follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Unrealized gains/(losses) on cash flow hedges ​ Items not yet recognized as a component of net periodic benefit cost ​ Total Balance as of December 31, 2022 ​ $ 16,912 ​ $ (9,948) ​ $ 6,964 Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive income ​ ​ (1,454) ​ ​ (224) ​ ​ (1,678) Amounts reclassified from accumulated other comprehensive income ​ ​ (2,384) ​ ​ — ​ ​ (2,384) Balance as of March 31, 2023 ​ $ 13,074 ​ $ (10,172) ​ $ 2,902 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ (4,863) ​ ​ (7,497) ​ ​ (12,360) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 9,058 ​ ​ 197 ​ ​ 9,255 Amounts reclassified from accumulated other comprehensive loss ​ ​ 1,704 ​ ​ — ​ ​ 1,704 Balance as of March 31, 2022 ​ $ 5,899 ​ $ (7,300) ​ $ (1,401) ​ ​ ​
Reclassification Out of Accumulated Other Comprehensive Income (Loss)	​ Amounts reclassified out of each component of accumulated other comprehensive income/(loss) follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ Statement of Operations Reclassifications of (gains)/losses on cash flow hedges: ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps entered into by the Company's ​ ​ ​ ​ ​ ​ ​ Equity in results of equity method joint venture investees ​ $ — ​ $ 130 ​ affiliated companies Interest rate swaps entered into by the Company's subsidiaries ​ ​ (1,782) ​ ​ 992 ​ Interest expense ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassifications of losses on discontinued hedging instruments ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap entered into by the Company's subsidiaries ​ ​ (602) ​ ​ 582 ​ Interest expense Total before and net of tax ​ $ (2,384) ​ $ 1,704 ​ ​ ​

REVENUE (Tables)

REVENUE (Tables)	3 Months Ended
	Mar. 31, 2023
REVENUE [Abstract]
Schedule of Disaggregated Revenue	The following table presents the Company’s revenues from leases accounted for under ASC 842 and revenues from services accounted for under ASC 606 for the three months ended March 31, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Three months ended March 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 108,799 ​ $ 150,779 ​ $ 259,578 Time charter revenues ​ ​ 9,686 ​ ​ 3,464 ​ ​ 13,150 Voyage charter revenues from non-variable lease payments ​ ​ 2,238 ​ ​ 326 ​ ​ 2,564 Voyage charter revenues from variable lease payments ​ ​ — ​ ​ 150 ​ ​ 150 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 11,688 ​ ​ — ​ ​ 11,688 Total shipping revenues ​ $ 132,411 ​ $ 154,719 ​ $ 287,130 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 27,310 ​ $ 56,452 ​ $ 83,762 Time charter revenues ​ ​ 3,724 ​ ​ 2,451 ​ ​ 6,175 Voyage charter revenues from non-variable lease payments ​ ​ 2,844 ​ ​ 3,047 ​ ​ 5,891 Voyage charter revenues from variable lease payments ​ ​ 14 ​ ​ (78) ​ ​ (64) Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 5,718 ​ ​ — ​ ​ 5,718 Total shipping revenues ​ $ 39,610 ​ $ 61,872 ​ $ 101,482 ​
Schedule of Contract Related Receivables, Assets and Liabilities with Customers	​ The following table provides information about receivables, contract assets and contract liabilities from contracts with customers, and significant changes in contract assets and liabilities balances, associated with revenue from services accounted for under ASC 606. Balances related to revenues from leases accounted for under ASC 842 are excluded from the table below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Voyage receivables - Billed receivables ​ Contract assets (Unbilled voyage receivables) ​ Contract liabilities (Deferred revenues and off hires) Opening balance as of January 1, 2023 ​ $ 9,452 ​ $ 1,866 ​ $ — Closing balance as of March 31, 2023 ​ ​ 6,116 ​ ​ 208 ​ ​ — ​

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2023
Lease [Abstract]
Schedule of lease cost	The Company currently has two major categories of leases - chartered-in vessels and leased office and other space. The expenses recognized during the three months ended March 31, 2023 and 2022 for the lease component of these leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Operating lease cost ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ Charter hire expenses ​ $ 1,067 ​ $ 2,418 ​ ​ ​ ​ ​ ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ 715 ​ ​ — Interest on lease liabilities ​ ​ 121 ​ ​ — ​ ​ ​ ​ ​ ​ ​ Office and other space ​ ​ ​ ​ ​ ​ General and administrative ​ ​ 228 ​ ​ 227 Voyage expenses ​ ​ 45 ​ ​ 43 ​ ​ ​ ​ ​ ​ ​ Short-term lease cost ​ ​ ​ ​ ​ ​ Vessel assets (1) ​ ​ ​ ​ ​ ​ Charter hire expenses ​ ​ 4,269 ​ ​ 1,479 Total lease cost ​ $ 6,445 ​ $ 4,167 (1) Excludes vessels spot chartered-in under operating leases and employed in the Crude Tankers Lightering business for periods of less than one month each, totaling $0.1 million and $0.4 million for the three months ended March 31, 2023 and 2022, respectively, including both lease and non-lease components. ​
Supplemental lease information	Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows used for operating leases ​ $ 937 ​ $ 2,486 Finance cash flows used for finance leases ​ ​ 23,955 ​ ​ — ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ March 31, 2023 ​ December 31, 2022 Operating lease right-of-use assets ​ $ 7,085 ​ $ 8,471 Finance lease right-of-use assets ​ ​ 22,001 ​ ​ 44,391 ​ ​ ​ ​ ​ ​ ​ Current portion of operating lease liabilities ​ $ (430) ​ $ (1,596) Current portion of finance lease liabilities ​ ​ (18,326) ​ ​ (41,870) Long-term operating lease liabilities ​ ​ (7,738) ​ ​ (7,740) Total operating and finance lease liabilities ​ $ (26,494) ​ $ (51,206) ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term - operating leases (1) ​ ​ 9.59 years ​ ​ 8.56 years Weighted average discount rate - operating leases (1) ​ ​ 4.37% ​ ​ 4.13% ​ (1) The weighted average remaining lease term and discount rate as of March 31, 2023 and December 31, 2022 exclude finance lease liabilities. Such finance leases had weighted average remaining lease terms of 0.01 years and 0.20 years at March 31, 2023 and December 31, 2022, respectively, and the annualized weighted average discount rate was 4.78% as of March 31, 2023 and December 31, 2022.
Schedule of lease maturity receivables	The future minimum revenues, before reduction for brokerage commissions, expected to be received on non-cancelable time charters for two VLCCs, two Suezmaxes, one LR2 and three MRs, and the related revenue days as of March 31, 2023 are as follows: ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Revenue Days 2023 ​ $ 46,606 ​ 1,709 2024 ​ ​ 45,948 ​ 1,688 2025 ​ ​ 13,484 ​ 462 2026 ​ ​ 11,315 ​ 365 2027 ​ ​ 11,315 ​ 365 Thereafter ​ ​ 23,870 ​ 770 Future minimum revenues ​ $ 152,537 ​ 5,359 ​
Office Space And Lightering Workboat Dock Space [Member]
Lease [Abstract]
Schedule of lease maturity payments	Payments of lease liabilities for office and other space as of March 31, 2023 are as follows: ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Amount 2023 ​ $ 159 2024 ​ ​ 973 2025 ​ ​ 998 2026 ​ ​ 1,024 2027 ​ ​ 1,077 Thereafter ​ ​ 5,831 Total lease payments ​ ​ 10,062 less imputed interest ​ ​ (2,086) Total operating lease liabilities ​ $ 7,976 ​
Bareboat Charters-In [Member]
Lease [Abstract]
Schedule of lease maturity payments	Payments of lease liabilities and related number of operating days under these operating and finance leases as of March 31, 2023 are as follows: ​ Bareboat Charters-in: ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Operating Days 2023 ​ $ 18,329 ​ 4 Total lease payments, including vessel purchase price ​ ​ 18,329 ​ 4 less imputed interest ​ ​ (3) ​ ​ Total finance lease liabilities ​ $ 18,326 ​ ​ ​
Time Charters-In [Member]
Lease [Abstract]
Schedule of lease maturity payments	Time Charters-in: ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Operating Days 2023 ​ $ 192 ​ 30 ​ ​ ​ ​ ​ ​ Total lease payments (lease component only) ​ ​ 192 ​ 30 less imputed interest ​ ​ — ​ ​ Total operating lease liabilities ​ $ 192 ​ ​ ​

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) segment property	Dec. 31, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Number of reportable segments | segment	2
Investments in and advances to affiliated companies	$ 34,076	$ 35,593
Other assets	9,441	$ 10,041
Revision of Prior Period, Adjustment [Member]
Property, Plant and Equipment [Line Items]
Investments in and advances to affiliated companies	(800)
Other assets	$ 800
Vessel/Fleet [Member]
Property, Plant and Equipment [Line Items]
Number of vessels in fleet | property	76
Maritime Equipment Not Including New Builds [Member]
Property, Plant and Equipment [Line Items]
Number of vessels in fleet | property	74
Maritime Equipment New Builds [Member]
Property, Plant and Equipment [Line Items]
Number of vessels in fleet | property	2

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Mar. 10, 2023	Jun. 02, 2022
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts receivable	$ 123		$ 261
Amortization of financing costs	1,300	$ 600
Proceeds from Insurance Settlement, Operating Activities	950	954
Debt instrument, face amount					$ 750,000
Amortization of time charter hire contracts acquired	0	340
Maritime Equipment New Builds [Member]
Summary Of Significant Accounting Policies [Line Items]
Interest costs capitalized	$ 1,700	$ 700
Revenue, Product and Service Benchmark [Member] | Product Concentration Risk [Member] | Pool Revenue Leases [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	96%		96%
Core Term Loan Facility, Core Transition Facility, Sinosure Credit Facility and 8.5% Senior Notes [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross	$ 13,700		$ 13,400
$750 Million Credit Facility
Summary Of Significant Accounting Policies [Line Items]
Debt instrument, face amount	750,000			$ 750,000
$750 Million Credit Facility and BoComm Lease Financing [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross	$ 6,300		$ 6,900

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES (Activity for allowance for credit losses) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Balance Beginning	$ 261
(Reversal of)/provision for expected credit losses	(138)
Balance Ending	$ 123

EARNINGS PER COMMON SHARE (Narr

EARNINGS PER COMMON SHARE (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	852,546	1,026,418
Dilutive awards	507,718	0
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Participating securities allocated a portion of income	48,890	87,117
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	637,223
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities		257,310

EARNINGS PER COMMON SHARE (Reco

EARNINGS PER COMMON SHARE (Reconciliation of Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
EARNINGS PER COMMON SHARE [Abstract]
Common Stockholders	$ 172,466	$ (13,006)
Participating securities	167	5
Net (loss)/income	$ 172,633	$ (13,001)

BUSINESS AND SEGMENT REPORTIN_2

BUSINESS AND SEGMENT REPORTING (Reportable Segments Information) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Revenues, services	$ 287,130	$ 101,482
Time charter equivalent revenues	283,320	97,975
Depreciation and amortization	29,548	27,000
Loss/(gain) on disposal of vessels and other assets, including impairments	(10,748)	(1,376)
Adjusted income/(loss) from vessel operations	186,203	3,349
Equity in income/(loss) of affiliated companies	0	5,597
Investments in and advances to affiliated companies		183,361
Adjusted total assets	2,264,607	2,268,112
Expenditures for vessels and vessel improvements	66,722	37,989
Payments for drydocking	12,978	17,570
Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	283,320
Time charter equivalent revenues		97,975
International Crude Tankers Segment [Member]
Segment Reporting Information [Line Items]
Revenues, services	132,411	39,610
Depreciation and amortization	17,226	15,152
Loss/(gain) on disposal of vessels and other assets, including impairments	0	1,843
Adjusted income/(loss) from vessel operations	84,541	(5,842)
Equity in income/(loss) of affiliated companies		5,597
Investments in and advances to affiliated companies		160,298
Adjusted total assets	1,455,356	1,465,035
Expenditures for vessels and vessel improvements	65,728	14,608
Payments for drydocking	2,128	7,660
International Crude Tankers Segment [Member] | Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	129,285
Time charter equivalent revenues		36,475
International Product Carriers Segment [Member]
Segment Reporting Information [Line Items]
Revenues, services	154,719	61,872
Depreciation and amortization	12,294	11,841
Loss/(gain) on disposal of vessels and other assets, including impairments	(10,748)	(3,219)
Adjusted income/(loss) from vessel operations	101,690	9,198
Equity in income/(loss) of affiliated companies		0
Investments in and advances to affiliated companies		23,063
Adjusted total assets	809,251	803,077
Expenditures for vessels and vessel improvements	994	23,381
Payments for drydocking	10,850	9,910
International Product Carriers Segment [Member] | Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	154,035
Time charter equivalent revenues		61,500
Other Segments [Member]
Segment Reporting Information [Line Items]
Revenues, services	0	0
Depreciation and amortization	28	7
Loss/(gain) on disposal of vessels and other assets, including impairments	0	0
Adjusted income/(loss) from vessel operations	(28)	(7)
Equity in income/(loss) of affiliated companies		0
Investments in and advances to affiliated companies		0
Adjusted total assets	0	0
Expenditures for vessels and vessel improvements	0	0
Payments for drydocking	0	0
Other Segments [Member] | Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	$ 0
Time charter equivalent revenues		$ 0

BUSINESS AND SEGMENT REPORTIN_3

BUSINESS AND SEGMENT REPORTING (Reconciliation of Time Charter Revenue to Shipping Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Time charter equivalent revenues	$ 283,320	$ 97,975
Add: Voyage expenses	3,810	3,507
Revenue, non lease	287,130	101,482
Time Charter Equivalent Services [Member]
Time charter equivalent revenues		$ 97,975
Revenue, non lease	$ 283,320

BUSINESS AND SEGMENT REPORTIN_4

BUSINESS AND SEGMENT REPORTING (Reconciliation of Income/(Loss) from Vessel Operations to Loss Before Reorganization) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total adjusted income/(loss) from vessel operations of all segments	$ 186,203	$ 3,349
General and administrative expenses	(11,246)	(10,166)
Reversal of expected credit losses	138
Third-party debt modification fees	(407)	(187)
Gain/(loss) on disposal of vessels and other assets, including impairments	10,748	1,376
Consolidated loss from vessel operations	185,298	(5,628)
Equity in income/(loss) of affiliated companies	0	5,597
Other income/(expense)	4,281	(226)
Interest expense	(16,947)	(12,740)
Income/(loss) before income taxes	172,632	(12,997)
Vessel Operations [Member]
Total adjusted income/(loss) from vessel operations of all segments	186,203	3,349
General and administrative expenses	(11,246)	(10,166)
Third-party debt modification fees	(407)	(187)
Gain/(loss) on disposal of vessels and other assets, including impairments	10,748	1,376
Consolidated loss from vessel operations	185,298	(5,628)
Equity in income/(loss) of affiliated companies	0	5,597
Other income/(expense)	4,281	(226)
Interest expense	(16,947)	(12,740)
Income/(loss) before income taxes	$ 172,632	$ (12,997)

BUSINESS AND SEGMENT REPORTIN_5

BUSINESS AND SEGMENT REPORTING (Reconciliation of Assets of Segments to Consolidated Amounts) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Segment Reporting Information [Line Items]
Adjusted total assets	$ 2,264,607		$ 2,268,112
Cash and cash equivalents	156,220	$ 243,744	74,553
Restricted cash	18,329		1,051
Short-term investments	105,000	80,000	0
Other unallocated amounts	27,374		22,877
Total assets	2,571,530	$ 2,615,334	2,366,593
Other Segments [Member]
Segment Reporting Information [Line Items]
Adjusted total assets	$ 0		$ 0

VESSELS (Narrative) (Details)

VESSELS (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use		$ 0	$ 1,697
Gain (loss) on disposition of property		10,748	3,073
Loss on contract termination			200
Vessels construction in progress	$ 123,940	85,662
Proceeds from disposal of vessels and other assets		20,021	$ 24,257
Dual Fuel LNG VLCC Under Construction [Member]
Property, Plant and Equipment [Line Items]
Remaining cost of construction of vessels		115,200
2 Aframaxes
Property, Plant and Equipment [Line Items]
Payments to acquire equipment	$ 43,000
MR Vessels
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition of property		$ 10,900

VARIABLE INTEREST ENTITIES (V_3

VARIABLE INTEREST ENTITIES (VIEs) (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) item	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 02, 2022 USD ($)
Variable Interest Entity [Line Items]
Accounts receivable, net, current	$ 248,029		$ 289,775
Payments on debt	$ 137,449	$ 46,265
Face amount				$ 750,000
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of commercial pools | item	6
Variable Interest Entity, Not Primary Beneficiary [Member] | FSO Joint Venture [Member]
Variable Interest Entity [Line Items]
Accounts receivable, net, current	$ 236,600

VARIABLE INTEREST ENTITIES (V_4

VARIABLE INTEREST ENTITIES (VIEs) (Balance Sheet Carrying Amounts Related to VIEs) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 31, 2022
Variable Interest Entity [Line Items]
Pool working capital deposits		$ 183,361
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Pool working capital deposits	$ 34,076

VARIABLE INTEREST ENTITIES (V_5

VARIABLE INTEREST ENTITIES (VIEs) (Comparison of Liability to Maximum Exposure to Loss) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Other Liabilities	$ 1,877	$ 1,875
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	$ 34,076

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended		3 Months Ended
	Jun. 02, 2022	May 22, 2022	May 31, 2022	Nov. 30, 2021	Mar. 31, 2023	Mar. 31, 2022	Mar. 10, 2023	Dec. 31, 2022
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount	$ 750,000
Derivative, notional amount			$ 358,600
Long-term debt					$ 932,679			$ 1,023,432
Net change in unrealized gains/(losses) on cash flow hedges					3,838	$ (10,762)
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred					6,600
Proceeds from derivative settlement			9,600
Derivative gain (loss)		$ 3,800		$ (1,900)
$750 Million Facility Term Loan
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount					750,000		$ 750,000	750,000
$750 Million Credit Facility
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount					750,000		$ 750,000
Derivative, notional amount	$ 475,000
Derivative, fixed interest rate	2.84%
Derivative, maturity date	Feb. 22, 2027
Long-term debt					350,699			$ 487,164
$390 Million Facility Term Loan
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount			390,000
$525 Million Facility Term Loan
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount			$ 525,000
$525 Million Facility Term Loan | Term loan
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount					$ 750,000

FAIR VALUE OF FINANCIAL INSTR_4

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Other Than Derivatives) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 10, 2023	Dec. 31, 2022	Jun. 02, 2022	May 31, 2022	Mar. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted cash	$ 18,329					$ 1,051
Debt face amount				$ 750,000
$390 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount					$ 390,000
$750 Million Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	750,000	$ 750,000
$750 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	750,000	$ 750,000	$ 750,000
$525 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount					$ 525,000
Term loan | $525 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	750,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	174,549		243,744
Short-term investments	105,000
Fair Value, Inputs, Level 2 [Member] | $390 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments			80,000
Fair Value, Inputs, Level 2 [Member] | $750 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(356,637)		(493,565)
Fair Value, Inputs, Level 2 [Member] | ING Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(22,396)		(22,917)
Fair Value, Inputs, Level 2 [Member] | Ocean Yield Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	(333,906)		(341,106)
Fair Value, Inputs, Level 2 [Member] | BoComm Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	(113,783)		(63,598)
Fair Value, Inputs, Level 2 [Member] | Toshin Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	(14,586)		(14,744)
Fair Value, Inputs, Level 2 [Member] | COSCO Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	(46,479)		(47,732)
Fair Value, Inputs, Level 2 [Member] | Hyuga Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(14,585)		(14,853)
Fair Value, Inputs, Level 2 [Member] | Kaiyo Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	(13,414)		(13,797)
Fair Value, Inputs, Level 2 [Member] | Kaisha Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease financing, Fair Value Disclosure	$ (13,508)		$ (13,704)

FAIR VALUE OF FINANCIAL INSTR_5

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current Portion of Derivative Assets [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 6,274	$ 6,987
Non Current Portion of Derivative Assets [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	2,138	4,662
Current Portion of Derivative Liabilities [Member]
Derivative Instruments in Hedges, Liabilities, at Fair Value	0	0
Non Current Portion of Derivative Liabilities [Member]
Derivative Instruments in Hedges, Liabilities, at Fair Value	0	0
Other Receivables [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	768	547
Designated as Hedging Instrument [Member] | Current Portion of Derivative Assets [Member] | Interest Rate Swap [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	6,274	6,987
Designated as Hedging Instrument [Member] | Non Current Portion of Derivative Assets [Member] | Interest Rate Swap [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	2,138	4,662
Designated as Hedging Instrument [Member] | Current Portion of Derivative Liabilities [Member] | Interest Rate Swap [Member]
Derivative Instruments in Hedges, Liabilities, at Fair Value	0	0
Designated as Hedging Instrument [Member] | Non Current Portion of Derivative Liabilities [Member] | Interest Rate Swap [Member]
Derivative Instruments in Hedges, Liabilities, at Fair Value	0	0
Designated as Hedging Instrument [Member] | Other Receivables [Member] | Interest Rate Swap [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 768	$ 547

FAIR VALUE OF FINANCIAL INSTR_6

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Effect of Cash Flow Hedging Relationships) (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
	May 22, 2022	Nov. 30, 2021	Mar. 31, 2023	Mar. 31, 2022
Derivative, gain (loss) on derivative, net	$ 3,800	$ (1,900)
Designated as Hedging Instrument [Member]
Total other comprehensive loss			$ (1,454)	$ 9,058
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Total other comprehensive loss			$ (1,454)	$ 9,058

FAIR VALUE OF FINANCIAL INSTR_7

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Effect of Cash Flow Hedging Relationships on Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	$ (2,384)	$ 1,704
Interest Expense [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	(2,384)	1,574
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	(602)	582
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	$ (1,782)	$ 992

FAIR VALUE OF FINANCIAL INSTR_8

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Values of Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Derivative Asset	$ 9,180	$ 12,196

DEBT (Schedule of Long-term Deb

DEBT (Schedule of Long-term Debt Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 10, 2023	Dec. 31, 2022	Jun. 02, 2022
Debt
Long-term debt	$ 932,679		$ 1,023,432
Less current portion	(155,525)		(162,854)
Long-term portion	777,154		860,578
Debt face amount				$ 750,000
$750 Million Facility Term Loan
Debt
Debt face amount	750,000	$ 750,000	750,000
Unamortized discount and deferred finance costs	5,937		6,400
$750 Million Credit Facility
Debt
Long-term debt	350,699		487,164
Debt face amount	750,000	$ 750,000
ING Credit Facility
Debt
Long-term debt	22,011		22,501
Unamortized discount and deferred finance costs	385		416
Ocean Yield Lease Financing
Debt
Long-term debt	330,845		337,908
Unamortized discount and deferred finance costs	3,061		3,198
BoComm Lease Financing
Debt
Long-term debt	126,786		71,140
Unamortized discount and deferred finance costs	2,005		917
Toshin Lease Financing
Debt
Long-term debt	15,006		15,215
Unamortized discount and deferred finance costs	354		370
COSCO Lease Financing
Debt
Long-term debt	45,355		46,544
Unamortized discount and deferred finance costs	1,123		1,187
Hyuga Lease Financing
Debt
Long-term debt	14,774		15,093
Unamortized discount and deferred finance costs	308		323
Kaiyo Lease Financing
Debt
Long-term debt	13,551		13,884
Unamortized discount and deferred finance costs	270		285
Kaisha Lease Financing
Debt
Long-term debt	13,652		13,983
Unamortized discount and deferred finance costs	$ 282		$ 298

DEBT (750 Million Credit Facili

DEBT (750 Million Credit Facility) (Details) $ in Thousands				3 Months Ended
	Mar. 14, 2023 USD ($)	Mar. 10, 2023 USD ($) item	May 20, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 02, 2022 USD ($)
Debt
Debt face amount							$ 750,000
Proceeds from long-term lines of credit				$ 0	$ 50,000
$750 Million Credit Facility
Debt
Debt face amount		$ 750,000		750,000
Credit facility, maximum borrowing capacity		366,300
Line of Credit Facility, Remaining Borrowing Capacity		257,400
Line of credit facility, amount outstanding		0
Scheduled future quarterly principal amortization		27,700	$ 30,200
Proceeds from sale of 2008-built MR	$ 20,200
Reduction in scheduled future quarterly principal amortization	400
Repayment of credit facility	$ 9,700	$ 97,000
Release of collateral vessel mortgages, number of MR product carriers | item		22
Additional borrowing capacity		$ 40,000
$750 Million Facility Term Loan
Debt
Debt face amount		$ 750,000		$ 750,000		$ 750,000

DEBT - BoComm Lease Financing R

DEBT - BoComm Lease Financing Relating to Dual-Fuel LNG VLCC Newbuilds (Details) - BoComm Lease Financing $ in Millions	Mar. 31, 2023 USD ($)	Nov. 15, 2021 USD ($) item
Debt Instrument [Line Items]
Sale Leaseback Transaction, Number of Vessels | item		3
Sale Leaseback Transaction, Net Sale Price		$ 244.8
Sale Leaseback Transaction Net Sale Price, Per Vehicle		$ 81.6
Line of credit facility, amount outstanding	$ 128.8
Line of Credit Facility, Remaining Borrowing Capacity	$ 115.2

DEBT (Debt Covenants) (Narrativ

DEBT (Debt Covenants) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 10, 2023	Jun. 02, 2022
Debt
Debt instrument, face amount			$ 750
Debt instrument, covenant compliance	The Company was in compliance with the financial and non-financial covenants under all of its financing arrangements as of March 31, 2023.
$750 Million Credit Facility
Debt
Debt instrument, face amount	$ 750	$ 750

DEBT (Schedule of Interest Expe

DEBT (Schedule of Interest Expense and Interest Paid) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 10, 2023	Jun. 02, 2022
Debt Instrument [Line Items]
Interest expense, debt	$ 18.4	$ 13.3
Interest paid, net	19.1	$ 11.8
Pre-delivery interest expenses	1.3
Debt instrument, face amount				$ 750
$750 Million Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 750		$ 750

DEBT ( Debt Modification, Repur

DEBT ( Debt Modification, Repurchases and Extinguishment) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 10, 2023	Jun. 02, 2022
Debt
Debt instrument, face amount			$ 750
Gains (losses) on repurchase and extinguishment of debt	$ 0.2
$750 Million Credit Facility
Debt
Debt instrument, face amount	$ 750	$ 750

CAPITAL STOCK AND STOCK COMPE_2

CAPITAL STOCK AND STOCK COMPENSATION (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended	3 Months Ended
	May 04, 2023	Apr. 11, 2023	May 08, 2022	Mar. 31, 2023	Mar. 31, 2023	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments of dividends					$ 98,313	$ 2,980
Repurchase of common shares					59,292	57,726
Weighted average price of shares purchased (per share)				$ 55.16	$ 55.16	$ 16.81
Supplemental cash dividend	$ 1.50				$ 1.88
Stock repurchase program, authorized amount				$ 60,000	$ 60,000
Dividends payable, amount per share	$ 0.12			$ 0.12	$ 0.12
Stock repurchase program, remaining authorized repurchase amount				$ 40,000	$ 40,000
Number of shares acquired under stock repurchase program					0	0
Amended and Restated the Rights Agreement (the "A&R Rights Agreement")
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Acquiring Person trigger threshold			17.50%
Purchase Price			$ 25
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends payable, date declared	May 04, 2023
Dividends payable, date of record	Jun. 14, 2023
Dividends payable, date to be paid	Jun. 28, 2023
Subsequent Event [Member] | Amended and Restated the Rights Agreement (the "A&R Rights Agreement")
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Acquiring Person trigger threshold		20%
Purchase Price		$ 50
Certain Senior Officers and Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised					12,940
Stock option average exercise price					$ 22.54
Shares issued net of shares for tax withholdings and exercise cost					3,319
Time Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares convertible into common shares per equity award represents					1
Time Based Restricted Stock [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted					52,890
Granted, per share					$ 51.37
Performance Shares [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted					52,890
Share-based Compensation Award, Tranche One [Member] | Performance Shares [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, per share				$ 51.37
Vesting percentage				50%
Return on investment capital performance period				3 years
Share-based Payment Arrangement, Tranche Two [Member] | Performance Shares [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, per share				$ 53.65
Vesting percentage				1%
Total shareholder return performance period				3 years
Share-based Payment Arrangement, Tranche Three [Member] | Performance Shares [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shareholder return peer group performance period				3 years

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred	$ 6.6

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Unrealized gains on derivative instruments	$ 13,074	$ 16,912
Items not yet recognized as a component of net periodic benefit cost (pension plans)	(10,172)	(9,948)
Accumulated other comprehensive loss	$ 2,902	$ 6,964

ACCUMULATED OTHER COMPREHENSI_5

ACCUMULATED OTHER COMPREHENSIVE INCOME (Changes in Components of AOCI, Net of Related Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Balance, beginning	$ 1,487,752	$ 1,170,332
Other comprehensive (loss)/income, net of tax	(4,062)	10,959
Balance, ending	1,557,283	1,165,450
Accumulated Other Comprehensive Loss [Member]
Balance, beginning	6,964	(12,360)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	(1,678)	9,255
Amounts reclassified from accumulated other comprehensive income/(loss)	(2,384)	1,704
Other comprehensive (loss)/income, net of tax	(4,062)	10,959
Balance, ending	2,902	(1,401)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance, beginning	16,912	(4,863)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	(1,454)	9,058
Amounts reclassified from accumulated other comprehensive income/(loss)	(2,384)	1,704
Balance, ending	13,074	5,899
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance, beginning	(9,948)	(7,497)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	(224)	197
Balance, ending	$ (10,172)	$ (7,300)

ACCUMULATED OTHER COMPREHENSI_6

ACCUMULATED OTHER COMPREHENSIVE INCOME (Amounts Reclassified out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Unrealized losses on available-for-sale securities:
Equity in income of affiliated companies	$ 172,632	$ (12,997)
Income (loss) from equity method investments	0	5,597
Interest expense	16,947	12,740
Other income	4,281	(226)
Total reclassified out of AOCL, before tax	(2,384)	1,704
Interest Rate Cap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Unrealized losses on available-for-sale securities:
Interest expense	(602)	582
Interest Rate Swap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Unrealized losses on available-for-sale securities:
Equity in income of affiliated companies	0	130
Interest expense	$ (1,782)	$ 992

REVENUE (Narrative) (Details)

REVENUE (Narrative) (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) property	Mar. 31, 2022 USD ($)
Revenues, Total | $	$ 287,130,000	$ 101,482,000
Capitalized contract cost, gross | $	$ 0
Lease cancellation period notice	90 days
Very Large Crude Carrier [Member]
Number of vessels party to contracts | property	2
LR2 Vessel [Member]
Number of vessels party to contracts | property	1
Suezmax
Number of vessels party to contracts | property	2
MR Vessel [Member]
Number of vessels party to contracts | $	3

REVENUE (Schedule of Disaggrega

REVENUE (Schedule of Disaggregated Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue, non lease	$ 287,130	$ 101,482
Shipping revenues	287,130	101,482
International Crude Tankers Segment [Member]
Revenue, non lease	132,411	39,610
Shipping revenues	132,411	39,610
International Product Carriers Segment [Member]
Revenue, non lease	154,719	61,872
Shipping revenues	154,719	61,872
Other Segments [Member]
Revenue, non lease	0	0
Pool Revenue Leases [Member]
Shipping revenues	259,578	83,762
Pool Revenue Leases [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	259,578	83,762
Pool Revenue Leases [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	108,799	27,310
Pool Revenue Leases [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	150,779	56,452
Voyage Charter Leases Non Variable Payments [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	2,564	5,891
Voyage Charter Leases Non Variable Payments [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	2,238	2,844
Voyage Charter Leases Non Variable Payments [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	326	3,047
Voyage Charter Leases Variable Payments [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases	150	(64)
Voyage Charter Leases Variable Payments [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases		14
Voyage Charter Leases Variable Payments [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases	150	(78)
Time and Bareboat Charter Leases [Member]
Shipping revenues	13,150	6,175
Time and Bareboat Charter Leases [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	13,150	6,175
Time and Bareboat Charter Leases [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	9,686	3,724
Time and Bareboat Charter Leases [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	3,464	2,451
Voyage Charter Leases [Member]
Shipping revenues	14,402	11,545
Voyage Charter Leases [Member] | Lightering Services Component [Member]
Revenue, non lease	11,688	5,718
Voyage Charter Leases [Member] | International Crude Tankers Segment [Member] | Lightering Services Component [Member]
Revenue, non lease	$ 11,688	$ 5,718

REVENUE (Schedule of Contract R

REVENUE (Schedule of Contract Related Receivables, Assets and Liabilities with Customers) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
REVENUE [Abstract]
Voyage receivables - receivables	$ 6,116	$ 9,452
Contract asset (voyage receivables unbilled receivables)	208	1,866
Contract liability (deferred revenues)	$ 0	$ 0

LEASES (Narrative) (Details)

LEASES (Narrative) (Details)	3 Months Ended
	Mar. 31, 2023 property lease
Leases [Line Items]
Number of major categories of leases | lease	2
Aframaxes [Member]
Leases [Line Items]
Vessels that have commitments to charter	1
Time Charters-In [Member] | LR1 Vessel [Member]
Leases [Line Items]
Vessels that have commitments to charter	2
Maximum
Leases [Line Items]
Excluded vessels chartered period	1 month

LEASES (Schedule of lease cost)

LEASES (Schedule of lease cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating lease, cost	$ 8,800	$ 7,309
Total lease cost	6,445	4,167
Vessel/Fleet [Member] | Charter Hire Expense [Member]
Operating lease, cost	1,067	2,418
Short-term lease, cost	4,269	1,479
Vessel/Fleet [Member] | Vessel Expense [Member]
Amortization of right-of-use assets	715	0
Interest on lease liabilities	121	0
Office Space [Member] | General and Administrative Expense [Member]
Operating lease, cost	228	227
Office Space [Member] | Voyage Expense [Member]
Operating lease, cost	45	43
Lightering Services Component [Member] | Vessel/Fleet [Member]
Short-term lease, cost	$ 100	$ 400

LEASES (Supplemental lease info

LEASES (Supplemental lease information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows used for operating leases	$ 937	$ 2,486
Finance cash flows used for finance leases	23,955	$ 0
Current portion of operating lease liabilities	(430)		$ (1,596)
Operating Lease, Liability, Noncurrent	7,738		7,740
Operating Lease, Right-of-Use Asset	7,085		8,471
Finance lease right-of-use assets	22,001		44,391
Current portion of finance lease liabilities	(18,326)		(41,870)
Total operating and finance lease liabilities	$ 26,494		$ 51,206
Operating Lease, Weighted Average Remaining Lease Term	9 years 7 months 2 days		8 years 6 months 21 days
Operating Lease, Weighted Average Discount Rate, Percent	4.37%		4.13%
Lessee, Finance Lease, Remaining Lease Term	3 days		2 months 12 days
Lessee, Finance Lease, Discount Rate	4.78%		4.78%

LEASES (Bareboat and Time Chart

LEASES (Bareboat and Time Charters-In) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Bareboat Charters-In [Member]
Leases [Line Items]
2023	$ 18,329
Total lease payments	18,329
less imputed interest	(3)
Total operating lease liabilities	$ 18,326
2023, operating days	4 days
Operating days, total	4 days
Time Charters-In [Member]
Leases [Line Items]
2023	$ 192
Total lease payments	192
Total operating lease liabilities	$ 192
2023, operating days	30 days
Operating days, total	30 days

LEASES (Future Minimum Lease Ob

LEASES (Future Minimum Lease Obligations for Office Space) (Details) - Office Space And Lightering Workboat Dock Space [Member] $ in Thousands	Mar. 31, 2023 USD ($)
Leases [Line Items]
2023	$ 159
2024	973
2025	998
2026	1,024
2027	1,077
Thereafter	5,831
Total lease payments	10,062
less imputed interest	(2,086)
Total operating lease liabilities	$ 7,976

LEASES (Future Minimum Revenues

LEASES (Future Minimum Revenues on Charters-Out) (Details) - Charters-Out [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Operating Leases, Future Minimum Payments Receivable [Abstract]
2023	$ 46,606
2024	45,948
2025	13,484
2026	11,315
2027	11,315
Thereafter	23,870
Net minimum lease payments	$ 152,537
2023, revenue days	1709 days
2024, revenue days	1688 days
2025, revenue days	462 days
2026, revenue days	365 days
2027, revenue days	365 days
Thereafter	770 days
Revenue Days	5359 days

CONTINGENCIES (Narrative) (Deta

CONTINGENCIES (Narrative) (Details)	3 Months Ended
	Mar. 31, 2023
Merchant Navy Ratings Pension Fund [Member]
Loss Contingencies [Line Items]
Multiemployer period of performance in the past	20 years