International Seaways (INSW) 10-Q 9 Aug 23 2023 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Aug. 07, 2023
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 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		48,889,609
Entity Central Index Key	0001679049
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
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 ($)	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 116,023,000	$ 243,744,000
Short-term investments	120,000,000	80,000,000
Restricted cash	0	0
Voyage receivables, net of allowance for credit losses of $56 and $261 including unbilled receivables of $234,392 and $279,567	241,088,000	289,775,000
Other receivables	12,840,000	12,583,000
Inventories	629,000	531,000
Prepaid expenses and other current assets	15,079,000	8,995,000
Advance payment on debt	46,427,000	0
Current portion of derivative asset	7,595,000	6,987,000
Total Current Assets	559,681,000	642,615,000
Vessels and other property, less accumulated depreciation of $378,341 and $331,903	1,977,639,000	1,680,010,000
Vessels construction in progress	0	123,940,000
Deferred drydock expenditures, net	69,887,000	65,611,000
Operating lease right-of-use assets	6,308,000	8,471,000
Finance lease right-of-use assets	0	44,391,000
Pool working capital deposits	32,521,000	35,593,000
Long-term derivative assets	4,462,000	4,662,000
Other assets	5,158,000	10,041,000
Total Assets	2,655,656,000	2,615,334,000
Current Liabilities:
Accounts payable, accrued expenses and other current liabilities	47,044,000	51,069,000
Current portion of operating lease liabilities	452,000	1,596,000
Current portion of finance lease liabilities	0	41,870,000
Current installments of long-term debt	199,785,000	162,854,000
Total Current Liabilities	247,281,000	257,389,000
Long-term operating lease liabilities	7,539,000	7,740,000
Long-term debt	778,266,000	860,578,000
Other liabilities	2,296,000	1,875,000
Total Liabilities	1,035,382,000	1,127,582,000
Commitments and contingencies
Equity:
Capital - 100,000,000 no par value shares authorized; 48,889,609 and 49,120,648 shares issued and outstanding	1,487,151,000	1,502,235,000
Retained earnings/(accumulated deficit)	127,368,000	(21,447,000)
Stockholders Equity Subtotal	1,614,519,000	1,480,788,000
Accumulated other comprehensive income	5,755,000	6,964,000
Total Equity	1,620,274,000	1,487,752,000
Total Liabilities and Equity	$ 2,655,656,000	$ 2,615,334,000

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED BALANCE SHEETS [Abstract]
Unbilled voyage receivable (in dollars)	$ 234,392	$ 279,567
Voyage receivables, allowance for credit losses	56	261
Vessels and other property, accumulated depreciation	$ 378,341	$ 331,903
Common stock, shares authorized	100,000,000	100,000,000
Common stock, no par value	$ 0	$ 0
Common stock, shares, issued	48,889,609	49,120,648
Common stock, shares, outstanding	48,889,609	49,120,648

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Shipping Revenues:
Shipping revenues	$ 292,203	$ 188,197	$ 579,333	$ 289,679
Operating Expenses:
Voyage expenses	3,868	2,658	7,678	6,165
Vessel expenses	65,151	59,563	123,920	119,880
Charter hire expenses	10,502	7,693	19,302	15,002
Depreciation and amortization	32,445	27,256	61,993	54,256
General and administrative	11,522	10,847	22,768	21,013
Third-party debt modification fees	13	900	420	1,087
Loss/(gain) on disposal of vessels and other assets, net of impairments	26	(8,102)	(10,722)	(9,478)
Total operating expenses	123,527	100,815	225,359	207,925
Income from vessel operations	168,676	87,382	353,974	81,754
Equity in results of affiliated companies		(5,162)	0	435
Operating income	168,676	82,220	353,974	82,189
Other income/(expense)	3,381	(574)	7,662	(800)
Income before interest expense and income taxes	172,057	81,646	361,636	81,389
Interest expense	(17,914)	(12,558)	(34,861)	(25,298)
Income before income taxes	154,143	69,088	326,775	56,091
Income tax provision	(381)	(52)	(380)	(56)
Net income	153,762	69,036	326,395	56,035
Net income/(loss) attributable to the Company	$ 153,762	$ 69,036	$ 326,395	$ 56,035
Weighted Average Number of Common Shares Outstanding:
Basic	49,029,784	49,602,181	49,083,897	49,586,847
Diluted	49,404,837	49,878,645	49,525,282	49,754,876
Per Share Amounts:
Basic net income/(loss) per share	$ 3.13	$ 1.39	$ 6.64	$ 1.13
Diluted net income/(loss) per share	$ 3.11	$ 1.38	$ 6.59	$ 1.12
Pool Revenue Leases [Member]
Shipping Revenues:
Shipping revenues	$ 247,591	$ 164,727	$ 507,169	$ 248,489
Time and Bareboat Charter Leases [Member]
Shipping Revenues:
Shipping revenues	26,112	8,133	39,262	14,308
Voyage Charter Leases [Member]
Shipping Revenues:
Shipping revenues	$ 18,500	$ 15,337	$ 32,902	$ 26,882

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Pool revenues, received from companies accounted for by the equity method	$ 86,325	$ 31,114	$ 178,032	$ 54,385

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) [Abstract]
Net income	$ 153,762	$ 69,036	$ 326,395	$ 56,035
Other comprehensive income/(loss), net of tax:
Net change in unrealized gains/(losses) on cash flow hedges	3,081	966	(757)	11,728
Defined benefit pension and other postretirement benefit plans:
Net change in unrecognized prior service costs	(30)	73	(60)	99
Net change in unrecognized actuarial losses	(198)	489	(392)	660
Other comprehensive income/(loss), net of tax	2,853	1,528	(1,209)	12,487
Comprehensive income	$ 156,615	$ 70,564	$ 325,186	$ 68,522

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash Flows from Operating Activities:
Net income	$ 326,395	$ 56,035
Items included in net income not affecting cash flows:
Depreciation and amortization	61,993	54,256
Loss on write-down of vessels and other assets	0	1,697
Amortization of debt discount and other deferred financing costs	3,128	1,955
Amortization of time charter hire contracts acquired	0	684
Deferred financing costs write-off	721	261
Stock compensation	3,873	2,728
Earnings of affiliated companies	20	(10,017)
Other - net	(1,560)	(327)
Items included in net income/(loss) related to investing and financing activities:
Gain on disposal of vessels and other assets, net	(10,722)	(11,175)
Loss on sale of investment in affiliated companies	0	9,512
Cash distributions from affiliated companies	0	2,250
Payments for drydocking	(18,992)	(25,789)
Insurance claims proceeds related to vessel operations	2,698	2,035
Changes in operating assets and liabilities:
Decrease/(increase) in receivables	48,687	(74,809)
Decrease in deferred revenue	(142)	0
Net change in inventories, prepaid expenses and other current assets and accounts payable, accrued expense, and other current and long-term liabilities	(1,643)	5,549
Net cash provided by operating activities	414,456	14,845
Cash Flows from Investing Activities:
Expenditures for vessels, vessel improvements and vessels under construction	(188,068)	(53,801)
Proceeds from disposal of vessels and other assets	20,070	79,614
Expenditures for other property	(586)	(509)
Proceeds from sale of investment in affiliated companies	0	140,069
Investments in short term time deposits	(175,000)	0
Pool working capital deposits	0	(838)
Proceeds from maturities of short term time deposits	135,000	0
Net cash (used in)/provided by investing activities	(208,584)	164,535
Cash Flows from Financing Activities:
Borrowings on long term debt, net of lenders' fees and deferred financing costs	0	641,050
Repayments of debt	(192,856)	(717,913)
Proceeds from sale and leaseback financing, net of issuance and deferred financing costs	169,717	60,076
Payments and advance payment on sale and leaseback financing and finance lease	(112,786)	(18,816)
Payments of deferred financing costs	(1,146)	(556)
Cash dividends paid	(177,565)	(8,941)
Repurchases of common stock	(13,948)	0
Cash paid to tax authority upon vesting or exercise of stock-based compensation	(5,009)	(1,493)
Net cash used in by financing activities	(333,593)	(46,593)
Net (decrease)/increase in cash, cash equivalents and restricted cash	(127,721)	132,787
Cash, cash equivalents and restricted cash at beginning of year	243,744	98,933
Cash, cash equivalents and restricted cash at end of period	$ 116,023	$ 231,720

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			0			56,035			0			0			56,035
Other comprehensive income/(loss)			0			0			12,487			0			12,487
Dividends declared			(8,941)			0			0						(8,941)
Forfeitures of vested restricted stock awards			(1,493)			0			0			0			(1,493)
Compensation relating to restricted stock units awards	$ 583	$ 1,607		$ 0	$ 0		$ 0	$ 0		$ 0	$ 0		$ 583	$ 1,607
Compensation relating to stock option awards			538			0			0			0			538
Balance, ending at Jun. 30, 2022			1,583,740			(353,303)			127			584			1,231,148
Balance, beginning at Mar. 31, 2022			1,588,606			(422,339)			(1,401)			584			1,165,450
Net income			0			69,036			0						69,036
Other comprehensive income/(loss)			0			0			1,528						1,528
Dividends declared			(5,963)			0			0						(5,963)
Forfeitures of vested restricted stock awards			(523)			0			0						(523)
Compensation relating to restricted stock units awards	287	1,106		0	0		0	0					287	1,106
Compensation relating to stock option awards			227			0			0						227
Balance, ending at Jun. 30, 2022			1,583,740			(353,303)			127			584			1,231,148
Balance, beginning at Dec. 31, 2022			1,502,235			(21,447)			6,964						1,487,752
Net income			0			326,395			0			0			326,395
Other comprehensive income/(loss)			0			0			(1,209)			0			(1,209)
Dividends declared			0			(177,580)			0			0			(177,580)
Forfeitures of vested restricted stock awards			(5,009)			0			0			0			(5,009)
Compensation relating to restricted stock units awards	491	3,043		0	0		0	0		$ 0	$ 0		491	3,043
Compensation relating to stock option awards			339			0			0			$ 0			339
Repurchase of common stock			(13,948)			0			0						(13,948)
Balance, ending at Jun. 30, 2023			1,487,151			127,368			5,755						1,620,274
Balance, beginning at Mar. 31, 2023			1,501,516			52,865			2,902						1,557,283
Net income			0			153,762			0						153,762
Other comprehensive income/(loss)			0			0			2,853						2,853
Dividends declared			0			(79,259)			0						(79,259)
Forfeitures of vested restricted stock awards			(2,390)			0			0						(2,390)
Compensation relating to restricted stock units awards	$ 223	$ 1,631		$ 0	$ 0		$ 0	$ 0					$ 223	$ 1,631
Compensation relating to stock option awards			119			0			0						119
Repurchase of common stock			(13,948)			0			0						(13,948)
Balance, ending at Jun. 30, 2023			$ 1,487,151			$ 127,368			$ 5,755						$ 1,620,274

BASIS OF PRESENTATION

BASIS OF PRESENTATION	6 Months Ended
	Jun. 30, 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 June 30, 2023, the Company’s operating fleet consisted of 74 wholly-owned or lease financed oceangoing vessels, engaged primarily in the transportation of crude oil and refined petroleum products in the International Flag trade through its wholly owned subsidiaries. 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 and six months ended June 30, 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	6 Months Ended
	Jun. 30, 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 ​ ​ (205) Balance at June 30, 2023 ​ $ 56 ​ During the three and six months ended June 30, 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% and 96% of consolidated voyage receivables at June 30, 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 $2.6 million for the three and six months ended June 30, 2023, respectively, and $1.1 million and $1.7 million for the three and six months ended June 30, 2022, respectively. ​ Vessels construction in progress — ​ Recently Issued Accounting Standards

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	6 Months Ended
	Jun. 30, 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 36,668 and 42,745 for the three and six months ended June 30, 2023, respectively, and 70,350 and 78,687 for the three and six months ended June 30, 2022, respectively. Such participating securities are allocated a portion of income, but not losses under the two-class method. As of June 30, 2023, there were 516,252 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 June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Net income allocated to: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Common Stockholders ​ $ 153,659 ​ $ 68,939 ​ $ 326,124 ​ $ 55,947 Participating securities ​ ​ 103 ​ ​ 97 ​ ​ 271 ​ ​ 88 ​ ​ $ 153,762 ​ $ 69,036 ​ $ 326,395 ​ $ 56,035 ​ For the three and six months ended June 30, 2023 earnings per share calculations, there were 375,053 and 441,385 dilutive equity awards outstanding, respectively. For the three and six months ended June 30, 2022 earnings per share calculations, there were 276,464 and 168,029 dilutive equity awards outstanding, respectively. Awards of 780,471 and 816,387 for the three and six months ended June 30, 2023, respectively, and 1,245,340 and 1,155,756 for the three and six months ended June 30, 2022, respectively, were not included in the computation of dilutive earnings per share because inclusion of these awards would be anti-dilutive.

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Three months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 152,168 ​ $ 140,035 ​ $ — ​ $ 292,203 Time charter equivalent revenues ​ ​ 148,913 ​ ​ 139,422 ​ ​ — ​ ​ 288,335 Depreciation and amortization ​ ​ 19,318 ​ ​ 13,101 ​ ​ 26 ​ ​ 32,445 Loss on disposal of vessels and other assets ​ ​ 25 ​ ​ 1 ​ ​ — ​ ​ 26 Adjusted income/(loss) from vessel operations ​ ​ 96,520 ​ ​ 83,743 ​ ​ (26) ​ ​ 180,237 Adjusted total assets at June 30, 2023 ​ ​ 1,554,542 ​ ​ 788,016 ​ ​ — ​ ​ 2,342,558 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 62,107 ​ $ 126,090 ​ $ — ​ $ 188,197 Time charter equivalent revenues ​ ​ 59,456 ​ ​ 126,083 ​ ​ — ​ ​ 185,539 Depreciation and amortization ​ ​ 15,187 ​ ​ 12,044 ​ ​ 25 ​ ​ 27,256 Gain on disposal of vessels and other assets, net of impairments ​ ​ (871) ​ ​ (7,231) ​ ​ — ​ ​ (8,102) Adjusted income/(loss) from vessel operations ​ ​ 15,565 ​ ​ 75,487 ​ ​ (25) ​ ​ 91,027 Equity in results of affiliated companies ​ ​ (5,162) ​ ​ — ​ ​ — ​ ​ (5,162) Investments in and advances to affiliated companies at June 30, 2022 ​ ​ 15,801 ​ ​ 24,031 ​ ​ — ​ ​ 39,832 Adjusted total assets at June 30, 2022 ​ ​ 1,313,221 ​ ​ 802,206 ​ ​ — ​ ​ 2,115,427 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Six months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 284,579 ​ $ 294,754 ​ $ — ​ $ 579,333 Time charter equivalent revenues ​ ​ 278,197 ​ ​ 293,458 ​ ​ — ​ ​ 571,655 Depreciation and amortization ​ ​ 36,544 ​ ​ 25,395 ​ ​ 54 ​ ​ 61,993 Loss/(gain) on disposal of vessels and other assets ​ ​ 25 ​ ​ (10,747) ​ ​ — ​ ​ (10,722) Adjusted income/(loss) from vessel operations ​ ​ 181,061 ​ ​ 185,433 ​ ​ (54) ​ ​ 366,440 Expenditures for vessels and vessel improvements ​ ​ 184,021 ​ ​ 4,047 ​ ​ — ​ ​ 188,068 Payments for drydocking ​ ​ 3,187 ​ ​ 15,805 ​ ​ — ​ ​ 18,992 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 101,717 ​ $ 187,962 ​ $ — ​ $ 289,679 Time charter equivalent revenues ​ ​ 95,932 ​ ​ 187,582 ​ ​ — ​ ​ 283,514 Depreciation and amortization ​ ​ 30,339 ​ ​ 23,885 ​ ​ 32 ​ ​ 54,256 Loss/(gain) on disposal of vessels and other assets, net of impairments ​ ​ 971 ​ ​ (10,449) ​ ​ — ​ ​ (9,478) Adjusted income/(loss) from vessel operations ​ ​ 9,723 ​ ​ 84,685 ​ ​ (32) ​ ​ 94,376 Equity in results of affiliated companies ​ ​ 435 ​ ​ — ​ ​ — ​ ​ 435 Expenditures for vessels and vessel improvements ​ ​ 26,747 ​ ​ 27,054 ​ ​ — ​ ​ 53,801 Payments for drydocking ​ ​ 12,369 ​ ​ 13,420 ​ ​ — ​ ​ 25,789 ​ ​ 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 June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Time charter equivalent revenues ​ $ 288,335 ​ $ 185,539 ​ $ 571,655 ​ $ 283,514 Add: Voyage expenses ​ ​ 3,868 ​ ​ 2,658 ​ ​ 7,678 ​ ​ 6,165 Shipping revenues ​ $ 292,203 ​ $ 188,197 ​ $ 579,333 ​ $ 289,679 ​ 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 before income taxes, as reported in the condensed consolidated statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Total adjusted income from vessel operations of all segments ​ $ 180,237 ​ $ 91,027 ​ $ 366,440 ​ $ 94,376 General and administrative expenses ​ ​ (11,522) ​ ​ (10,847) ​ ​ (22,768) ​ ​ (21,013) Third-party debt modification fees ​ ​ (13) ​ ​ (900) ​ ​ (420) ​ ​ (1,087) Merger and integration related costs ​ ​ — ​ ​ ​ ​ ​ — ​ ​ — (Loss)/gain on disposal of vessels and other assets, net of impairments ​ ​ (26) ​ ​ 8,102 ​ ​ 10,722 ​ ​ 9,478 Consolidated income from vessel operations ​ ​ 168,676 ​ ​ 87,382 ​ ​ 353,974 ​ ​ 81,754 Equity in results of affiliated companies ​ ​ — ​ ​ (5,162) ​ ​ — ​ ​ 435 Other income/(expense) ​ ​ 3,381 ​ ​ (574) ​ ​ 7,662 ​ ​ (800) Interest expense ​ ​ (17,914) ​ ​ (12,558) ​ ​ (34,861) ​ ​ (25,298) Income before income taxes ​ $ 154,143 ​ $ 69,088 ​ $ 326,775 ​ $ 56,091 ​ Reconciliations of total assets of the segments to amounts included in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 ​ June 30, 2022 Adjusted total assets of all segments ​ $ 2,342,558 ​ $ 2,115,427 Corporate unrestricted cash and cash equivalents ​ ​ 116,023 ​ ​ 230,666 Restricted cash ​ ​ — ​ ​ 1,054 Short-term investments ​ ​ 120,000 ​ ​ — Advance payment on debt ​ ​ 46,427 ​ ​ — Other unallocated amounts ​ ​ 30,648 ​ ​ 17,094 Consolidated total assets ​ $ 2,655,656 ​ $ 2,364,241 ​

VESSELS

VESSELS	6 Months Ended
	Jun. 30, 2023
VESSELS [Abstract]
VESSELS	Note 5 — Vessels: ​ Impairment of Vessels and Other Property ​ During the six months ended June 30, 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 June 30, 2023 and no held-for-use impairment indicators existed for the Company’s vessels as of March 31, 2023 or June 30, 2023. ​ The Company recognized a loss of approximately $0.2 million during the first six months ended June 30, 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 ​ 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 and April 4, 2023, the Company completed the purchase of the two Aframaxes. ​ On March 7, 2023, the first of Company’s three newbuild dual-fuel LNG VLCCs was delivered by the shipyard. The second and third of the Company’s three newbuild dual-fuel LNG VLCCs were delivered to the Company on April 11, 2023 and May 24, 2023, respectively. All three vessels commenced employment under seven-year time charter contracts with an oil major shortly after delivery. ​ On August 8, 2023, the Company entered into agreements to construct two dual-fuel ready LNG 73,600 dwt LR1 Product Carriers at K Shipbuilding Co., Ltd.’s shipyard, subject to certain conditions customary to similar transactions. The two vessels are scheduled for delivery during the second half of 2025. The total construction cost for the vessels will be approximately $115 million, which will be paid for through a combination of long-term financing and available liquidity. The Company also entered into option agreements exercisable during the third quarter of 2023 to construct two other identical vessels at the same shipyard for delivery during the first quarter of 2026. ​ Disposal/Sales of Vessels ​ On March 14, 2023, the Company delivered a 2008-built MR to its buyer and recognized a gain of $10.9 million. ​

VARIABLE INTEREST ENTITIES (VIE

VARIABLE INTEREST ENTITIES (VIEs)	6 Months Ended
	Jun. 30, 2023
VARIABLE INTEREST ENTITIES (VIEs) [Abstract]
VARIABLE INTEREST ENTITIES (VIEs)	Note 6 — Variable Interest Entities (“VIEs”): ​ Unconsolidated VIEs ​ As of June 30, 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 June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ Condensed Pool working capital deposits ​ ​ ​ ​ $ 32,521 ​ 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 June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Condensed ​ Maximum Exposure to Other Liabilities ​ $ – ​ $ 32,521 ​ In addition, as of June 30, 2023, the Company had approximately $225.6 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 June 30, 2023.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES	6 Months Ended
	Jun. 30, 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) ​ June 30, 2023 ​ December 31, 2022 ​ Fair Value Level Cash and cash equivalents (1) ​ $ 116,023 ​ $ 243,744 ​ ​ Level 1 Short-term investments (2) ​ ​ 120,000 ​ ​ 80,000 ​ ​ Level 1 $750 Million Facility Term Loan (3) ​ ​ (301,751) ​ ​ (493,565) ​ ​ Level 2 ING Credit Facility (3) ​ ​ (21,875) ​ ​ (22,917) ​ ​ Level 2 Ocean Yield Lease Financing (3) ​ ​ (326,626) ​ ​ (341,106) ​ ​ Level 2 BoComm Lease Financing (4) ​ ​ (209,044) ​ ​ (63,598) ​ ​ Level 2 Toshin Lease Financing (4) ​ ​ (13,877) ​ ​ (14,744) ​ ​ Level 2 Hyuga Lease Financing (4) ​ ​ (13,980) ​ ​ (14,853) ​ ​ Level 2 COSCO Lease Financing (3) ​ ​ (45,225) ​ ​ (47,732) ​ ​ Level 2 Kaiyo Lease Financing (4) ​ ​ (12,842) ​ ​ (13,797) ​ ​ Level 2 Kaisha Lease Financing (4) ​ ​ (12,934) ​ ​ (13,704) ​ ​ Level 2 (1) Current restricted cash was nil at June 30, 2023 and December 31, 2022, respectively. (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 June 30, 2023, approximately $3.4 million of the gain is expected to amortize out of accumulated other comprehensive income to earnings over the next 12 months. ​ Also, as of June 30, 2023, approximately $1.8 million of the loss with regard 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 June 30, 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 June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 7,595 ​ $ 4,462 ​ $ — ​ $ — ​ $ 942 Total ​ $ 7,595 ​ $ 4,462 ​ $ — ​ $ — ​ $ 942 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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 excluding amounts reclassified from accumulated other comprehensive income, including hedges of equity method investees, for the three and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 5,848 ​ $ 1,873 ​ $ 4,393 ​ $ 10,932 Total other comprehensive income ​ $ 5,848 ​ $ 1,873 ​ $ 4,393 ​ $ 10,932 ​ 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 and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (2,204) ​ $ (1,478) ​ $ (3,985) ​ $ (487) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discontinued hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap ​ ​ (563) ​ ​ 571 ​ ​ (1,165) ​ ​ 1,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total interest expense ​ $ (2,767) ​ $ (907) ​ $ (5,150) ​ $ 666 ​ 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) ​ June 30, 2023 ​ December 31, 2022 ​ Fair Value Level Derivative Assets (interest rate swaps) ​ $ 12,999 ​ $ 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	6 Months Ended
	Jun. 30, 2023
DEBT [Abstract]
DEBT	Note 8 — Debt: ​ Debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 December 31, 2022 $750 Million Facility Term Loan, due 2027, net of unamortized deferred finance costs of $4,673 and $6,400 ​ $ 297,078 ​ $ 487,164 ING Credit Facility, due 2026, net of unamortized deferred finance costs of $355 and $416 ​ ​ 21,520 ​ ​ 22,501 Ocean Yield Lease Financing, due 2031, net of unamortized deferred finance costs of $2,924 and $3,198 ​ ​ 323,702 ​ ​ 337,908 BoComm Lease Financing, due 2030, net of unamortized deferred finance costs of $4,537 and $917 ​ ​ 236,037 ​ ​ 71,140 Toshin Lease Financing, due 2031, net of unamortized deferred finance costs of $333 and $370 ​ ​ 14,572 ​ ​ 15,215 COSCO Lease Financing, due 2028, net of unamortized deferred finance costs of $1,060 and $1,187 ​ ​ 44,165 ​ ​ 46,544 Hyuga Lease Financing, due 2031, net of unamortized deferred finance costs of $294 and $323 ​ ​ 14,450 ​ ​ 15,093 Kaiyo Lease Financing, due 2030, net of unamortized deferred finance costs of $256 and $285 ​ ​ 13,212 ​ ​ 13,884 Kaisha Lease Financing, due 2030, net of unamortized deferred finance costs of $267 and $298 ​ ​ 13,315 ​ ​ 13,983 ​ ​ ​ 978,051 ​ ​ 1,023,432 Less current portion ​ ​ (199,785) ​ ​ (162,854) Long-term portion ​ $ 778,266 ​ $ 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. On May 19, 2023, the Company made another mandatory prepayment of $28.9 million towards the $750 Million Facility Term Loan, which resulted in the release of ​ 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 three newbuilds were delivered to the Company on March 7, 2023, April 11, 2023, and May 24, 2023, respectively. The BoComm Lease Financing provided the funding of $244.8 million in aggregate ( $81.6 million each vessel) over the course of the construction and delivery of the three vessels. Under the lease financing arrangements, each vessel is subject to a seven-year bareboat charter commencing on delivery of each vessel at a bareboat rate of $21,700 per day, with purchase options exercisable commencing at the end of the second year. ​ 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 on the interest rate reset date on May 7, 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 on the interest rate reset date on May 12, 2023. ​ COSCO Lease Financing ​ In May 2023, the Company tendered notice of its intention to exercise its options to purchase one 2013-built Aframax and one 2014-built LR2, which were bareboat chartered-in under COSCO Lease Financing arrangements as at June 30, 2023. The aggregate purchase price for the two vessels of $46.4 million, consisted of the $45.2 million remaining debt balance and $1.2 million of purchase option premiums. The Company made an advance payment on June 30, 2023 and the purchase closed on July 3, 2023. ​ ​ Debt Covenants ​ The Company was in compliance with the financial and non-financial covenants under all of its financing arrangements as of June 30, 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 and six months ended June 30, 2023 was $18.2 million and $36.5 million, respectively ​ ​ Debt Modifications, Repurchases and Extinguishments ​ During the first six months of 2023, the Company recognized a net loss of $0.7 million, which is included in other income/(expense) in the accompanying condensed consolidated statement of operations. The net loss reflects (i) a $0.2 million 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”); and (ii) $0.4 million write-off of unamortized deferred financing costs associated with the mandatory principal prepayment of the $750 Million Facility Term Loan in May 2023 in connection with the release of a 2017-built Suezmax from vessel collateral package.

TAXES

TAXES	6 Months Ended
	Jun. 30, 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 June 30, 2023, the Company qualifies 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, 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	6 Months Ended
	Jun. 30, 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 Common Stock ​ In June 2023, the Company awarded a total of 26,878 restricted common stock shares to its non-employee directors. The weighted average fair market value of INSW’s stock on the measurement date of such awards was $37.94 per share. Such restricted share awards vest in full on the earlier of the next annual meeting of the stockholders or June 6, 2024, subject to each director continuing to provide services to INSW through such date. The restricted share awards granted may not be transferred, pledged, assigned or otherwise encumbered prior to vesting. Prior to the vesting date, a holder of restricted share awards otherwise has all the rights of a shareholder of INSW, including the right to vote such shares and the right to receive dividends paid with respect to such shares at the same time as common shareholders generally. ​ Restricted Stock Units and Stock Options ​ During the six months ended June 30, 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 market 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 time-based RSUs awarded will vest in equal installments on each of the first three anniversaries of the grant date. ​ During the six months ended June 30, 2023, the Company also awarded 52,890 performance-based RSUs to certain of its senior officers and employees. Each performance-based RSU represents a contingent right to receive shares of INSW common stock 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 six months ended June 30, 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 ​ On February 27, 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 on March 28, 2023. ​ On May 4, 2023, the Company’s Board of Directors declared a regular quarterly cash dividend of $0.12 per share of common stock and a supplemental dividend of $1.50 per share of common stock. Pursuant to such dividend declarations, the Company made dividend payments totaling $79.3 million on June 28, 2023. ​ On August 8, 2023, the Company’s Board of Directors declared a regular quarterly cash dividend of $0.12 per share of common stock and a supplemental dividend of $1.30 per share of common stock. Both dividends will be paid on September 27, 2023 to stockholders of record as of September 13, 2023. ​ ​ Share Repurchases ​ During the three months ended June 30, 2023, the Company repurchased and retired 366,483 shares of its common stock in open-market purchases, at an average price of $38.03 per share, for a total cost of $13.9 million. As of June 30, 2023, the remaining buyback authorization under the Company’s $60.0 million stock repurchase program expiring in December 2023 was $26.1 million. No shares were acquired under repurchase programs during the six months ended June 30, 2022. In August 2023, the Company’s Board of Directors authorized an increase in the share repurchase program to $50.0 million from $26.1 million. In connection with the settlement of vested restricted stock units and the exercise of stock options, the Company repurchased 62,045 and 121,337 shares of common stock during the three and six months ended June 30, 2023, respectively, at an average cost of $38.52 and $46.65, 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. Similarly, the Company repurchased 26,753 and 84,479 shares of common stock during the three and six months ended June 30, 2022, respectively, at an average cost of $19.54 and $17.67, respectively, per share. ​ 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	6 Months Ended
	Jun. 30, 2023
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME	Note 11 — Accumulated Other Comprehensive Income: ​ The components of accumulated other comprehensive income, net of related taxes, in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 December 31, 2022 Unrealized gains on derivative instruments ​ $ 16,155 ​ $ 16,912 Items not yet recognized as a component of net periodic benefit cost (pension plans) ​ ​ (10,400) ​ ​ (9,948) ​ ​ $ 5,755 ​ $ 6,964 ​ ​ The changes in the balances of each component of accumulated other comprehensive income/(loss), net of related taxes, during the three and six months ended June 30, 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 March 31, 2023 ​ $ 13,074 ​ $ (10,172) ​ $ 2,902 Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive income ​ ​ 5,848 ​ ​ (228) ​ ​ 5,620 Amounts reclassified from accumulated other comprehensive income ​ ​ (2,767) ​ ​ — ​ ​ (2,767) Balance as of June 30, 2023 ​ $ 16,155 ​ $ (10,400) ​ $ 5,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of March 31, 2022 ​ $ 5,899 ​ ​ (7,300) ​ ​ (1,401) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 1,873 ​ ​ 562 ​ ​ 2,435 Amounts reclassified from accumulated other comprehensive loss ​ ​ (907) ​ ​ — ​ ​ (907) Balance as of June 30, 2022 ​ $ 6,865 ​ $ (6,738) ​ $ 127 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Unrealized 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 ​ ​ 4,393 ​ ​ (452) ​ ​ 3,941 Amounts reclassified from accumulated other comprehensive income ​ ​ (5,150) ​ ​ — ​ ​ (5,150) Balance as of June 30, 2023 ​ $ 16,155 ​ $ (10,400) ​ $ 5,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ (4,863) ​ ​ (7,497) ​ $ (12,360) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 10,932 ​ ​ 759 ​ ​ 11,691 Amounts reclassified from accumulated other comprehensive loss ​ ​ 796 ​ ​ — ​ ​ 796 Balance as of June 30, 2022 ​ $ 6,865 ​ $ (6,738) ​ $ 127 ​ ​ Amounts reclassified out of each component of accumulated other comprehensive income/(loss) follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 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 ​ ​ (2,204) ​ ​ (1,478) ​ ​ (3,985) ​ ​ (487) ​ Interest expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassifications of losses on discontinued hedging instruments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap entered into by the Company’s subsidiaries ​ ​ (563) ​ ​ 571 ​ ​ (1,165) ​ ​ 1,153 ​ Interest expense Total before and net of tax ​ $ (2,767) ​ $ (907) ​ $ (5,150) ​ $ 796 ​ ​ ​ At June 30, 2023, the Company expects that it will reclassify $8.2 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	6 Months Ended
	Jun. 30, 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 June 30, 2023, the Company is a party to time charter out contracts with customers on four VLCCs, two Suezmaxes, one LR2 and four MRs, with expiry dates ranging from July 2023 to April 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 tables present the Company’s revenues from leases accounted for under ASC 842 and revenues from services accounted for under ASC 606 for the three and six months ended June 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Three months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 119,639 ​ $ 127,952 ​ $ 247,591 Time charter revenues ​ ​ 18,570 ​ ​ 7,542 ​ ​ 26,112 Voyage charter revenues from non-variable lease payments ​ ​ 1,417 ​ ​ 4,541 ​ ​ 5,958 Voyage charter revenues from variable lease payments ​ ​ 66 ​ ​ — ​ ​ 66 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 12,476 ​ ​ — ​ ​ 12,476 Total shipping revenues ​ $ 152,168 ​ $ 140,035 ​ $ 292,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 45,166 ​ $ 119,561 ​ $ 164,727 Time charter revenues ​ ​ 6,204 ​ ​ 1,929 ​ ​ 8,133 Voyage charter revenues from non-variable lease payments ​ ​ 2,237 ​ ​ 4,593 ​ ​ 6,830 Voyage charter revenues from variable lease payments ​ ​ 48 ​ ​ 7 ​ ​ 55 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 8,452 ​ ​ — ​ ​ 8,452 Total shipping revenues ​ $ 62,107 ​ $ 126,090 ​ $ 188,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Six months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 228,438 ​ $ 278,731 ​ $ 507,169 Time and bareboat charter revenues ​ ​ 28,256 ​ ​ 11,006 ​ ​ 39,262 Voyage charter revenues from non-variable lease payments ​ ​ 3,655 ​ ​ 4,867 ​ ​ 8,522 Voyage charter revenues from variable lease payments ​ ​ 66 ​ ​ 150 ​ ​ 216 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 24,164 ​ ​ — ​ ​ 24,164 Total shipping revenues ​ $ 284,579 ​ $ 294,754 ​ $ 579,333 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 72,476 ​ $ 176,013 ​ $ 248,489 Time and bareboat charter revenues ​ ​ 9,928 ​ ​ 4,380 ​ ​ 14,308 Voyage charter revenues from non-variable lease payments (1) ​ ​ 5,081 ​ ​ 7,640 ​ ​ 12,721 Voyage charter revenues from variable lease payments ​ ​ 62 ​ ​ (71) ​ ​ (9) Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 14,170 ​ ​ — ​ ​ 14,170 Total shipping revenues ​ $ 101,717 ​ $ 187,962 ​ $ 289,679 (1) Includes $0.9 million of loss of hire proceeds received during the second quarter of 2022. 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 June 30, 2023 ​ ​ 2,887 ​ ​ 3,536 ​ ​ — ​ 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 and six months ended June 30, 2023 and 2022, respectively. ​ Costs to Obtain or Fulfill a Contract ​ As of June 30, 2023, there were no unamortized deferred costs of obtaining or fulfilling a contract.

LEASES

LEASES	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2023 and 2022 for the lease component of these leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Operating lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Charter hire expenses ​ $ 678 ​ $ 2,481 ​ $ 1,745 ​ $ 4,899 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ 16 ​ ​ — ​ ​ 731 ​ ​ — Interest on lease liabilities ​ ​ 3 ​ ​ — ​ ​ 124 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office and other space ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ General and administrative ​ ​ 228 ​ ​ 228 ​ ​ 456 ​ ​ 455 Voyage expenses ​ ​ 45 ​ ​ 43 ​ ​ 90 ​ ​ 86 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Charter hire expenses ​ ​ 5,154 ​ ​ 1,533 ​ ​ 9,423 ​ ​ 3,012 Total lease cost ​ $ 6,124 ​ $ 4,285 ​ $ 12,569 ​ $ 8,452 (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 $1.6 million and $1.7 million for the three and six months ended June 30, 2023, respectively, compared with $0.7 million and $1.1 million for the three and six months ended June 30, 2022, respectively, including both lease and non-lease components. ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows used for operating leases ​ $ 1,685 ​ $ 5,035 Finance cash flows used for finance leases ​ ​ 42,284 ​ ​ — ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 ​ December 31, 2022 Operating lease right-of-use assets ​ $ 6,308 ​ $ 8,471 Finance lease right-of-use assets ​ ​ — ​ ​ 44,391 ​ ​ ​ ​ ​ ​ ​ Current portion of operating lease liabilities ​ $ (452) ​ $ (1,596) Current portion of finance lease liabilities ​ ​ — ​ ​ (41,870) Long-term operating lease liabilities ​ ​ (7,539) ​ ​ (7,740) Total operating and finance lease liabilities ​ $ (7,991) ​ $ (51,206) ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term – operating leases (1) ​ ​ 9.65 years ​ ​ 8.56 years Weighted average discount rate – operating leases (1) ​ ​ 4.44% ​ ​ 4.13% (1) The weighted average remaining lease term and discount rate as of December 31, 2022 exclude finance lease liabilities. Such finance leases had weighted average remaining lease terms of 0.20 years at December 31, 2022 and the annualized weighted average discount rate was 4.78% as of December 31, 2022. ​ 1. Charters-in of vessel assets: ​ In June 2023, the Company entered a two-year time charter-in contract for one LR1 The vessel was delivered to the Company on July 12, 2023. The minimum lease payments (including both lease and non-lease components) due under this time charter-in will be $5,937, $12,627, and $5,624 in 2023, 2024 and 2025, respectively. ​ 2. ​ 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 June 30, 2023 are as follows: ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Amount 2023 (1) ​ $ (105) 2024 ​ ​ 1,167 2025 ​ ​ 998 2026 ​ ​ 1,024 2027 ​ ​ 1,077 Thereafter ​ ​ 5,831 Total lease payments ​ ​ 9,992 less imputed interest ​ ​ (2,001) Total operating lease liabilities ​ $ 7,991 (1) ​ 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 the deduction of brokerage commissions, expected to be received on non-cancelable time charters for four VLCCs, two Suezmaxes, one Aframax, one LR2 and four MRs, and the related revenue days as of June 30, 2023 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Revenue Days 2023 ​ $ 50,500 ​ 1,764 2024 ​ ​ 91,515 ​ 3,152 2025 ​ ​ 58,926 ​ 1,922 2026 ​ ​ 42,098 ​ 1,336 2027 ​ ​ 33,945 ​ 1,095 Thereafter ​ ​ 75,051 ​ 2,421 Future minimum revenues ​ $ 352,035 ​ 11,690 ​ 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. ​ ​

CONTINGENCIES

CONTINGENCIES	6 Months Ended
	Jun. 30, 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 June 30, 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 June 30, 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. ​ In late July 2023, one of the Company’s vessels was arrested in connection with a commercial dispute arising earlier in the year, with the arresting party seeking approximately $24 million in security. The Company is defending itself vigorously against the arrest. As this matter is in the early stages, the Company is currently unable to predict the outcome of this complaint, and no estimate of liability has been accrued for this matter at this time. ​ ​

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 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 ​ ​ (205) Balance at June 30, 2023 ​ $ 56 ​ During the three and six months ended June 30, 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% and 96% of consolidated voyage receivables at June 30, 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 $2.6 million for the three and six months ended June 30, 2023, respectively, and $1.1 million and $1.7 million for the three and six months ended June 30, 2022, respectively.
Vessels construction in progress	Vessels construction in progress — ​
Recently adopted / issued accounting standards	Recently Issued Accounting Standards

CONTINGENCIES (Policy)

CONTINGENCIES (Policy)	6 Months Ended
	Jun. 30, 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)	6 Months Ended
	Jun. 30, 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 ​ ​ (205) Balance at June 30, 2023 ​ $ 56

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	6 Months Ended
	Jun. 30, 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 June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Net income allocated to: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Common Stockholders ​ $ 153,659 ​ $ 68,939 ​ $ 326,124 ​ $ 55,947 Participating securities ​ ​ 103 ​ ​ 97 ​ ​ 271 ​ ​ 88 ​ ​ $ 153,762 ​ $ 69,036 ​ $ 326,395 ​ $ 56,035

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING (Tables)	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Three months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 152,168 ​ $ 140,035 ​ $ — ​ $ 292,203 Time charter equivalent revenues ​ ​ 148,913 ​ ​ 139,422 ​ ​ — ​ ​ 288,335 Depreciation and amortization ​ ​ 19,318 ​ ​ 13,101 ​ ​ 26 ​ ​ 32,445 Loss on disposal of vessels and other assets ​ ​ 25 ​ ​ 1 ​ ​ — ​ ​ 26 Adjusted income/(loss) from vessel operations ​ ​ 96,520 ​ ​ 83,743 ​ ​ (26) ​ ​ 180,237 Adjusted total assets at June 30, 2023 ​ ​ 1,554,542 ​ ​ 788,016 ​ ​ — ​ ​ 2,342,558 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 62,107 ​ $ 126,090 ​ $ — ​ $ 188,197 Time charter equivalent revenues ​ ​ 59,456 ​ ​ 126,083 ​ ​ — ​ ​ 185,539 Depreciation and amortization ​ ​ 15,187 ​ ​ 12,044 ​ ​ 25 ​ ​ 27,256 Gain on disposal of vessels and other assets, net of impairments ​ ​ (871) ​ ​ (7,231) ​ ​ — ​ ​ (8,102) Adjusted income/(loss) from vessel operations ​ ​ 15,565 ​ ​ 75,487 ​ ​ (25) ​ ​ 91,027 Equity in results of affiliated companies ​ ​ (5,162) ​ ​ — ​ ​ — ​ ​ (5,162) Investments in and advances to affiliated companies at June 30, 2022 ​ ​ 15,801 ​ ​ 24,031 ​ ​ — ​ ​ 39,832 Adjusted total assets at June 30, 2022 ​ ​ 1,313,221 ​ ​ 802,206 ​ ​ — ​ ​ 2,115,427 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Other ​ Totals Six months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 284,579 ​ $ 294,754 ​ $ — ​ $ 579,333 Time charter equivalent revenues ​ ​ 278,197 ​ ​ 293,458 ​ ​ — ​ ​ 571,655 Depreciation and amortization ​ ​ 36,544 ​ ​ 25,395 ​ ​ 54 ​ ​ 61,993 Loss/(gain) on disposal of vessels and other assets ​ ​ 25 ​ ​ (10,747) ​ ​ — ​ ​ (10,722) Adjusted income/(loss) from vessel operations ​ ​ 181,061 ​ ​ 185,433 ​ ​ (54) ​ ​ 366,440 Expenditures for vessels and vessel improvements ​ ​ 184,021 ​ ​ 4,047 ​ ​ — ​ ​ 188,068 Payments for drydocking ​ ​ 3,187 ​ ​ 15,805 ​ ​ — ​ ​ 18,992 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shipping revenues ​ $ 101,717 ​ $ 187,962 ​ $ — ​ $ 289,679 Time charter equivalent revenues ​ ​ 95,932 ​ ​ 187,582 ​ ​ — ​ ​ 283,514 Depreciation and amortization ​ ​ 30,339 ​ ​ 23,885 ​ ​ 32 ​ ​ 54,256 Loss/(gain) on disposal of vessels and other assets, net of impairments ​ ​ 971 ​ ​ (10,449) ​ ​ — ​ ​ (9,478) Adjusted income/(loss) from vessel operations ​ ​ 9,723 ​ ​ 84,685 ​ ​ (32) ​ ​ 94,376 Equity in results of affiliated companies ​ ​ 435 ​ ​ — ​ ​ — ​ ​ 435 Expenditures for vessels and vessel improvements ​ ​ 26,747 ​ ​ 27,054 ​ ​ — ​ ​ 53,801 Payments for drydocking ​ ​ 12,369 ​ ​ 13,420 ​ ​ — ​ ​ 25,789 ​ ​
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 June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Time charter equivalent revenues ​ $ 288,335 ​ $ 185,539 ​ $ 571,655 ​ $ 283,514 Add: Voyage expenses ​ ​ 3,868 ​ ​ 2,658 ​ ​ 7,678 ​ ​ 6,165 Shipping revenues ​ $ 292,203 ​ $ 188,197 ​ $ 579,333 ​ $ 289,679
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	​ Reconciliations of total adjusted income from vessel operations of the segments to income before income taxes, as reported in the condensed consolidated statements of operations follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Total adjusted income from vessel operations of all segments ​ $ 180,237 ​ $ 91,027 ​ $ 366,440 ​ $ 94,376 General and administrative expenses ​ ​ (11,522) ​ ​ (10,847) ​ ​ (22,768) ​ ​ (21,013) Third-party debt modification fees ​ ​ (13) ​ ​ (900) ​ ​ (420) ​ ​ (1,087) Merger and integration related costs ​ ​ — ​ ​ ​ ​ ​ — ​ ​ — (Loss)/gain on disposal of vessels and other assets, net of impairments ​ ​ (26) ​ ​ 8,102 ​ ​ 10,722 ​ ​ 9,478 Consolidated income from vessel operations ​ ​ 168,676 ​ ​ 87,382 ​ ​ 353,974 ​ ​ 81,754 Equity in results of affiliated companies ​ ​ — ​ ​ (5,162) ​ ​ — ​ ​ 435 Other income/(expense) ​ ​ 3,381 ​ ​ (574) ​ ​ 7,662 ​ ​ (800) Interest expense ​ ​ (17,914) ​ ​ (12,558) ​ ​ (34,861) ​ ​ (25,298) Income before income taxes ​ $ 154,143 ​ $ 69,088 ​ $ 326,775 ​ $ 56,091
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) ​ June 30, 2023 ​ June 30, 2022 Adjusted total assets of all segments ​ $ 2,342,558 ​ $ 2,115,427 Corporate unrestricted cash and cash equivalents ​ ​ 116,023 ​ ​ 230,666 Restricted cash ​ ​ — ​ ​ 1,054 Short-term investments ​ ​ 120,000 ​ ​ — Advance payment on debt ​ ​ 46,427 ​ ​ — Other unallocated amounts ​ ​ 30,648 ​ ​ 17,094 Consolidated total assets ​ $ 2,655,656 ​ $ 2,364,241

VARIABLE INTEREST ENTITIES (V_2

VARIABLE INTEREST ENTITIES (VIEs) (Tables)	6 Months Ended
	Jun. 30, 2023
VARIABLE INTEREST ENTITIES (VIEs) [Abstract]
Schedule of Variable Interest Entities	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ Condensed Pool working capital deposits ​ ​ ​ ​ $ 32,521
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 ​ $ – ​ $ 32,521

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Tables)	6 Months Ended
	Jun. 30, 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) ​ June 30, 2023 ​ December 31, 2022 ​ Fair Value Level Cash and cash equivalents (1) ​ $ 116,023 ​ $ 243,744 ​ ​ Level 1 Short-term investments (2) ​ ​ 120,000 ​ ​ 80,000 ​ ​ Level 1 $750 Million Facility Term Loan (3) ​ ​ (301,751) ​ ​ (493,565) ​ ​ Level 2 ING Credit Facility (3) ​ ​ (21,875) ​ ​ (22,917) ​ ​ Level 2 Ocean Yield Lease Financing (3) ​ ​ (326,626) ​ ​ (341,106) ​ ​ Level 2 BoComm Lease Financing (4) ​ ​ (209,044) ​ ​ (63,598) ​ ​ Level 2 Toshin Lease Financing (4) ​ ​ (13,877) ​ ​ (14,744) ​ ​ Level 2 Hyuga Lease Financing (4) ​ ​ (13,980) ​ ​ (14,853) ​ ​ Level 2 COSCO Lease Financing (3) ​ ​ (45,225) ​ ​ (47,732) ​ ​ Level 2 Kaiyo Lease Financing (4) ​ ​ (12,842) ​ ​ (13,797) ​ ​ Level 2 Kaisha Lease Financing (4) ​ ​ (12,934) ​ ​ (13,704) ​ ​ Level 2 (1) Current restricted cash was nil at June 30, 2023 and December 31, 2022, respectively. (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 June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 7,595 ​ $ 4,462 ​ $ — ​ $ — ​ $ 942 Total ​ $ 7,595 ​ $ 4,462 ​ $ — ​ $ — ​ $ 942 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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 excluding amounts reclassified from accumulated other comprehensive income, including hedges of equity method investees, for the three and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ 5,848 ​ $ 1,873 ​ $ 4,393 ​ $ 10,932 Total other comprehensive income ​ $ 5,848 ​ $ 1,873 ​ $ 4,393 ​ $ 10,932 ​ 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 and six months ended June 30, 2023 and 2022 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ $ (2,204) ​ $ (1,478) ​ $ (3,985) ​ $ (487) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discontinued hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap ​ ​ (563) ​ ​ 571 ​ ​ (1,165) ​ ​ 1,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total interest expense ​ $ (2,767) ​ $ (907) ​ $ (5,150) ​ $ 666 ​
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents the fair values, which are pre-tax, for assets and liabilities measured on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 ​ December 31, 2022 ​ Fair Value Level Derivative Assets (interest rate swaps) ​ $ 12,999 ​ $ 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)	6 Months Ended
	Jun. 30, 2023
DEBT [Abstract]
Schedule of Long-term Debt Instruments	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 December 31, 2022 $750 Million Facility Term Loan, due 2027, net of unamortized deferred finance costs of $4,673 and $6,400 ​ $ 297,078 ​ $ 487,164 ING Credit Facility, due 2026, net of unamortized deferred finance costs of $355 and $416 ​ ​ 21,520 ​ ​ 22,501 Ocean Yield Lease Financing, due 2031, net of unamortized deferred finance costs of $2,924 and $3,198 ​ ​ 323,702 ​ ​ 337,908 BoComm Lease Financing, due 2030, net of unamortized deferred finance costs of $4,537 and $917 ​ ​ 236,037 ​ ​ 71,140 Toshin Lease Financing, due 2031, net of unamortized deferred finance costs of $333 and $370 ​ ​ 14,572 ​ ​ 15,215 COSCO Lease Financing, due 2028, net of unamortized deferred finance costs of $1,060 and $1,187 ​ ​ 44,165 ​ ​ 46,544 Hyuga Lease Financing, due 2031, net of unamortized deferred finance costs of $294 and $323 ​ ​ 14,450 ​ ​ 15,093 Kaiyo Lease Financing, due 2030, net of unamortized deferred finance costs of $256 and $285 ​ ​ 13,212 ​ ​ 13,884 Kaisha Lease Financing, due 2030, net of unamortized deferred finance costs of $267 and $298 ​ ​ 13,315 ​ ​ 13,983 ​ ​ ​ 978,051 ​ ​ 1,023,432 Less current portion ​ ​ (199,785) ​ ​ (162,854) Long-term portion ​ $ 778,266 ​ $ 860,578

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	6 Months Ended
	Jun. 30, 2023
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive income, net of related taxes, in the condensed consolidated balance sheets follow: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 December 31, 2022 Unrealized gains on derivative instruments ​ $ 16,155 ​ $ 16,912 Items not yet recognized as a component of net periodic benefit cost (pension plans) ​ ​ (10,400) ​ ​ (9,948) ​ ​ $ 5,755 ​ $ 6,964 ​ ​ The changes in the balances of each component of accumulated other comprehensive income/(loss), net of related taxes, during the three and six months ended June 30, 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 March 31, 2023 ​ $ 13,074 ​ $ (10,172) ​ $ 2,902 Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive income ​ ​ 5,848 ​ ​ (228) ​ ​ 5,620 Amounts reclassified from accumulated other comprehensive income ​ ​ (2,767) ​ ​ — ​ ​ (2,767) Balance as of June 30, 2023 ​ $ 16,155 ​ $ (10,400) ​ $ 5,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of March 31, 2022 ​ $ 5,899 ​ ​ (7,300) ​ ​ (1,401) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 1,873 ​ ​ 562 ​ ​ 2,435 Amounts reclassified from accumulated other comprehensive loss ​ ​ (907) ​ ​ — ​ ​ (907) Balance as of June 30, 2022 ​ $ 6,865 ​ $ (6,738) ​ $ 127 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Unrealized 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 ​ ​ 4,393 ​ ​ (452) ​ ​ 3,941 Amounts reclassified from accumulated other comprehensive income ​ ​ (5,150) ​ ​ — ​ ​ (5,150) Balance as of June 30, 2023 ​ $ 16,155 ​ $ (10,400) ​ $ 5,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ (4,863) ​ ​ (7,497) ​ $ (12,360) Current period change, excluding amounts reclassified ​ ​ ​ ​ ​ ​ ​ ​ ​ from accumulated other comprehensive loss ​ ​ 10,932 ​ ​ 759 ​ ​ 11,691 Amounts reclassified from accumulated other comprehensive loss ​ ​ 796 ​ ​ — ​ ​ 796 Balance as of June 30, 2022 ​ $ 6,865 ​ $ (6,738) ​ $ 127 ​
Reclassification Out of Accumulated Other Comprehensive Income (Loss)	​ Amounts reclassified out of each component of accumulated other comprehensive income/(loss) follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 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 ​ ​ (2,204) ​ ​ (1,478) ​ ​ (3,985) ​ ​ (487) ​ Interest expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassifications of losses on discontinued hedging instruments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swap entered into by the Company’s subsidiaries ​ ​ (563) ​ ​ 571 ​ ​ (1,165) ​ ​ 1,153 ​ Interest expense Total before and net of tax ​ $ (2,767) ​ $ (907) ​ $ (5,150) ​ $ 796 ​ ​ ​

REVENUE (Tables)

REVENUE (Tables)	6 Months Ended
	Jun. 30, 2023
REVENUE [Abstract]
Schedule of Disaggregated Revenue	The following tables present the Company’s revenues from leases accounted for under ASC 842 and revenues from services accounted for under ASC 606 for the three and six months ended June 30, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Three months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 119,639 ​ $ 127,952 ​ $ 247,591 Time charter revenues ​ ​ 18,570 ​ ​ 7,542 ​ ​ 26,112 Voyage charter revenues from non-variable lease payments ​ ​ 1,417 ​ ​ 4,541 ​ ​ 5,958 Voyage charter revenues from variable lease payments ​ ​ 66 ​ ​ — ​ ​ 66 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 12,476 ​ ​ — ​ ​ 12,476 Total shipping revenues ​ $ 152,168 ​ $ 140,035 ​ $ 292,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 45,166 ​ $ 119,561 ​ $ 164,727 Time charter revenues ​ ​ 6,204 ​ ​ 1,929 ​ ​ 8,133 Voyage charter revenues from non-variable lease payments ​ ​ 2,237 ​ ​ 4,593 ​ ​ 6,830 Voyage charter revenues from variable lease payments ​ ​ 48 ​ ​ 7 ​ ​ 55 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 8,452 ​ ​ — ​ ​ 8,452 Total shipping revenues ​ $ 62,107 ​ $ 126,090 ​ $ 188,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Crude ​ Product ​ ​ ​ (Dollars in thousands) ​ Tankers ​ Carriers ​ Totals Six months ended June 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 228,438 ​ $ 278,731 ​ $ 507,169 Time and bareboat charter revenues ​ ​ 28,256 ​ ​ 11,006 ​ ​ 39,262 Voyage charter revenues from non-variable lease payments ​ ​ 3,655 ​ ​ 4,867 ​ ​ 8,522 Voyage charter revenues from variable lease payments ​ ​ 66 ​ ​ 150 ​ ​ 216 Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 24,164 ​ ​ — ​ ​ 24,164 Total shipping revenues ​ $ 284,579 ​ $ 294,754 ​ $ 579,333 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues from leases ​ ​ ​ ​ ​ ​ ​ ​ ​ Pool revenues ​ $ 72,476 ​ $ 176,013 ​ $ 248,489 Time and bareboat charter revenues ​ ​ 9,928 ​ ​ 4,380 ​ ​ 14,308 Voyage charter revenues from non-variable lease payments (1) ​ ​ 5,081 ​ ​ 7,640 ​ ​ 12,721 Voyage charter revenues from variable lease payments ​ ​ 62 ​ ​ (71) ​ ​ (9) Revenues from services ​ ​ ​ ​ ​ ​ ​ ​ ​ Voyage charter revenues from lightering services ​ ​ 14,170 ​ ​ — ​ ​ 14,170 Total shipping revenues ​ $ 101,717 ​ $ 187,962 ​ $ 289,679 (1) Includes $0.9 million of loss of hire proceeds received during the second quarter of 2022.
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 June 30, 2023 ​ ​ 2,887 ​ ​ 3,536 ​ ​ — ​

LEASES (Tables)

LEASES (Tables)	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2023 and 2022 for the lease component of these leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 ​ ​ 2023 ​ ​ 2022 Operating lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Charter hire expenses ​ $ 678 ​ $ 2,481 ​ $ 1,745 ​ $ 4,899 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ 16 ​ ​ — ​ ​ 731 ​ ​ — Interest on lease liabilities ​ ​ 3 ​ ​ — ​ ​ 124 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office and other space ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ General and administrative ​ ​ 228 ​ ​ 228 ​ ​ 456 ​ ​ 455 Voyage expenses ​ ​ 45 ​ ​ 43 ​ ​ 90 ​ ​ 86 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vessel assets (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Charter hire expenses ​ ​ 5,154 ​ ​ 1,533 ​ ​ 9,423 ​ ​ 3,012 Total lease cost ​ $ 6,124 ​ $ 4,285 ​ $ 12,569 ​ $ 8,452 (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 $1.6 million and $1.7 million for the three and six months ended June 30, 2023, respectively, compared with $0.7 million and $1.1 million for the three and six months ended June 30, 2022, respectively, including both lease and non-lease components.
Supplemental lease information	Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, (Dollars in thousands) ​ ​ 2023 ​ ​ 2022 Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows used for operating leases ​ $ 1,685 ​ $ 5,035 Finance cash flows used for finance leases ​ ​ 42,284 ​ ​ — ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ June 30, 2023 ​ December 31, 2022 Operating lease right-of-use assets ​ $ 6,308 ​ $ 8,471 Finance lease right-of-use assets ​ ​ — ​ ​ 44,391 ​ ​ ​ ​ ​ ​ ​ Current portion of operating lease liabilities ​ $ (452) ​ $ (1,596) Current portion of finance lease liabilities ​ ​ — ​ ​ (41,870) Long-term operating lease liabilities ​ ​ (7,539) ​ ​ (7,740) Total operating and finance lease liabilities ​ $ (7,991) ​ $ (51,206) ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term – operating leases (1) ​ ​ 9.65 years ​ ​ 8.56 years Weighted average discount rate – operating leases (1) ​ ​ 4.44% ​ ​ 4.13% (1) The weighted average remaining lease term and discount rate as of December 31, 2022 exclude finance lease liabilities. Such finance leases had weighted average remaining lease terms of 0.20 years at December 31, 2022 and the annualized weighted average discount rate was 4.78% as of December 31, 2022.
Schedule of lease maturity receivables	The future minimum revenues, before the deduction of brokerage commissions, expected to be received on non-cancelable time charters for four VLCCs, two Suezmaxes, one Aframax, one LR2 and four MRs, and the related revenue days as of June 30, 2023 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ Amount ​ Revenue Days 2023 ​ $ 50,500 ​ 1,764 2024 ​ ​ 91,515 ​ 3,152 2025 ​ ​ 58,926 ​ 1,922 2026 ​ ​ 42,098 ​ 1,336 2027 ​ ​ 33,945 ​ 1,095 Thereafter ​ ​ 75,051 ​ 2,421 Future minimum revenues ​ $ 352,035 ​ 11,690
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 June 30, 2023 are as follows: ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ Amount 2023 (1) ​ $ (105) 2024 ​ ​ 1,167 2025 ​ ​ 998 2026 ​ ​ 1,024 2027 ​ ​ 1,077 Thereafter ​ ​ 5,831 Total lease payments ​ ​ 9,992 less imputed interest ​ ​ (2,001) Total operating lease liabilities ​ $ 7,991 (1)

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) $ in Thousands	6 Months Ended
	Jun. 30, 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	$ 32,521	$ 35,593
Other assets	5,158	$ 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
Maritime Equipment Not Including New Builds [Member]
Property, Plant and Equipment [Line Items]
Number of vessels in fleet | property	74

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Mar. 10, 2023	Jun. 02, 2022
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts receivable	$ 56,000		$ 56,000		$ 261,000
Reversal of expected credit losses			205,000
Amortization of financing costs	1,300,000	$ 1,100,000	2,600,000	$ 1,700,000
Restricted Cash and Cash Equivalents, Current	0		0		$ 0
Proceeds from Insurance Settlement, Operating Activities			2,698,000	2,035,000
Debt instrument, face amount							$ 750,000,000
Amortization of time charter hire contracts acquired			0	684,000
Maritime Equipment New Builds [Member]
Summary Of Significant Accounting Policies [Line Items]
Interest costs capitalized	500,000	$ 800,000	$ 2,300,000	$ 1,500,000
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	14,700,000		$ 14,700,000		$ 13,400,000
$750 Million Credit Facility
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross	$ 3,300,000		$ 3,300,000
Debt instrument, face amount						$ 750,000,000
$750 Million Credit Facility and BoComm Lease Financing [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross					$ 6,900,000

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES (Activity for allowance for credit losses) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Balance Beginning	$ 261
Provision for expected credit losses	205
Balance Ending	$ 56

EARNINGS PER COMMON SHARE (Narr

EARNINGS PER COMMON SHARE (Narrative) (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Participating securities allocated a portion of income	36,668	70,350	42,745	78,687
Antidilutive securities excluded from computation of earnings per share, amount	780,471	1,245,340	816,387	1,155,756
Dilutive awards	375,053	276,464	441,385	168,029
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities			516,252
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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
EARNINGS PER COMMON SHARE [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic	$ 153,659	$ 68,939	$ 326,124	$ 55,947
Net Income (Loss) Available to Common Stockholders, Diluted	153,659	68,939	326,124	55,947
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic	103	97	271	88
Net (loss)/income	$ 153,762	$ 69,036	$ 326,395	$ 56,035

BUSINESS AND SEGMENT REPORTIN_2

BUSINESS AND SEGMENT REPORTING (Reportable Segments Information) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Revenues, services	$ 292,203	$ 188,197	$ 579,333	$ 289,679
Time charter equivalent revenues	288,335	185,539	571,655	283,514
Depreciation and amortization	32,445	27,256	61,993	54,256
Loss/(gain) on disposal of vessels and other assets, including impairments	26	(8,102)	(10,722)	(9,478)
Adjusted income/(loss) from vessel operations	180,237	91,027	366,440	94,376
Equity in income/(loss) of affiliated companies		(5,162)	0	435
Investments in and advances to affiliated companies		39,832		39,832
Adjusted total assets	2,342,558	2,115,427	2,342,558	2,115,427
Expenditures for vessels and vessel improvements			188,068	53,801
Payments for drydocking			18,992	25,789
Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	288,335
Time charter equivalent revenues		185,539	571,655
International Crude Tankers Segment [Member]
Segment Reporting Information [Line Items]
Revenues, services	152,168	62,107	284,579	101,717
Time charter equivalent revenues				95,932
Depreciation and amortization	19,318	15,187	36,544	30,339
Loss/(gain) on disposal of vessels and other assets, including impairments	25	(871)	25	971
Adjusted income/(loss) from vessel operations	96,520	15,565	181,061	9,723
Equity in income/(loss) of affiliated companies		(5,162)		435
Investments in and advances to affiliated companies		15,801		15,801
Adjusted total assets	1,554,542	1,313,221	1,554,542	1,313,221
Expenditures for vessels and vessel improvements			184,021	26,747
Payments for drydocking			3,187	12,369
International Crude Tankers Segment [Member] | Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	148,913
Time charter equivalent revenues		59,456	278,197
International Product Carriers Segment [Member]
Segment Reporting Information [Line Items]
Revenues, services	140,035	126,090	294,754	187,962
Time charter equivalent revenues				187,582
Depreciation and amortization	13,101	12,044	25,395	23,885
Loss/(gain) on disposal of vessels and other assets, including impairments	1	(7,231)	(10,747)	(10,449)
Adjusted income/(loss) from vessel operations	83,743	75,487	185,433	84,685
Equity in income/(loss) of affiliated companies		0
Investments in and advances to affiliated companies		24,031		24,031
Adjusted total assets	788,016	802,206	788,016	802,206
Expenditures for vessels and vessel improvements			4,047	27,054
Payments for drydocking			15,805	13,420
International Product Carriers Segment [Member] | Time Charter Equivalent Services [Member]
Segment Reporting Information [Line Items]
Revenues, services	139,422
Time charter equivalent revenues		126,083	293,458
Other Segments [Member]
Segment Reporting Information [Line Items]
Revenues, services	0	0
Depreciation and amortization	26	25	54	32
Loss/(gain) on disposal of vessels and other assets, including impairments	0	0
Adjusted income/(loss) from vessel operations	(26)	(25)	(54)	(32)
Equity in income/(loss) of affiliated companies		0
Investments in and advances to affiliated companies		0		0
Adjusted total assets	0	0	$ 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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Time charter equivalent revenues	$ 288,335	$ 185,539	$ 571,655	$ 283,514
Add: Voyage expenses	3,868	2,658	7,678	6,165
Revenue, non lease	292,203	188,197	579,333	$ 289,679
Time Charter Equivalent Services [Member]
Time charter equivalent revenues		$ 185,539	$ 571,655
Revenue, non lease	$ 288,335

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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total adjusted income/(loss) from vessel operations of all segments	$ 180,237	$ 91,027	$ 366,440	$ 94,376
General and administrative expenses	(11,522)	(10,847)	(22,768)	(21,013)
Third-party debt modification fees	(13)	(900)	(420)	(1,087)
Gain/(loss) on disposal of vessels and other assets, including impairments	(26)	8,102	10,722	9,478
Consolidated loss from vessel operations	168,676	87,382	353,974	81,754
Equity in income/(loss) of affiliated companies		(5,162)	0	435
Other income/(expense)	3,381	(574)	7,662	(800)
Interest expense	(17,914)	(12,558)	(34,861)	(25,298)
Income before income taxes	154,143	69,088	326,775	56,091
Vessel Operations [Member]
Total adjusted income/(loss) from vessel operations of all segments	180,237	91,027	366,440	94,376
General and administrative expenses	(11,522)	(10,847)	(22,768)	(21,013)
Third-party debt modification fees	(13)	(900)	(420)	(1,087)
Gain/(loss) on disposal of vessels and other assets, including impairments	(26)	8,102	10,722	9,478
Consolidated loss from vessel operations	168,676	87,382	353,974	81,754
Equity in income/(loss) of affiliated companies		(5,162)	0	435
Other income/(expense)	3,381	(574)	7,662	(800)
Interest expense	(17,914)	(12,558)	(34,861)	(25,298)
Income before income taxes	$ 154,143	$ 69,088	$ 326,775	$ 56,091

BUSINESS AND SEGMENT REPORTIN_5

BUSINESS AND SEGMENT REPORTING (Reconciliation of Assets of Segments to Consolidated Amounts) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Segment Reporting Information [Line Items]
Adjusted total assets	$ 2,342,558		$ 2,115,427
Cash and cash equivalents	116,023	$ 243,744	230,666
Restricted cash, current and noncurrent	0		1,054
Short-term investments	120,000	80,000	0
Advance payment on debt	46,427	0	0
Other unallocated amounts	30,648		17,094
Total assets	2,655,656	$ 2,615,334	2,364,241
Other Segments [Member]
Segment Reporting Information [Line Items]
Adjusted total assets	$ 0		$ 0

VESSELS (Narrative) (Details)

VESSELS (Narrative) (Details) - USD ($)			1 Months Ended	6 Months Ended
	Aug. 08, 2023	Mar. 14, 2023	Dec. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	May 25, 2023
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use				$ 0	$ 1,697,000
Gain (loss) on disposition of property				10,722,000	11,175,000
Loss on contract termination				200,000
Vessels construction in progress			$ 123,940,000	0
Vessel's construction completed and placed into service							$ 3
Proceeds from disposal of vessels and other assets				$ 20,070,000	$ 79,614,000
Two 2009 Aframaxes Vessels [Member]
Property, Plant and Equipment [Line Items]
Payments to acquire equipment			$ 43,000,000
MR Vessels
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition of property		$ 10,900,000
LNG 73,600 DWT Long Range One Product Carrier [Member]
Property, Plant and Equipment [Line Items]
Expected construction costs	$ 115,000,000
Vessels construction in progress	2
LNG 73,600 DWT Long Range One Product Carrier [Member] | Subsequent Event [Member]
Property, Plant and Equipment [Line Items]
Vessels construction in progress	$ 2					$ 2

VARIABLE INTEREST ENTITIES (V_3

VARIABLE INTEREST ENTITIES (VIEs) (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($) item	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 02, 2022 USD ($)
Variable Interest Entity [Line Items]
Accounts receivable, net, current	$ 241,088		$ 289,775
Payments on debt	192,856	$ 717,913
Face amount				$ 750,000
Proceeds from Sale of Equity Method Investments	$ 0	$ 140,069
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	$ 225,600

VARIABLE INTEREST ENTITIES (V_4

VARIABLE INTEREST ENTITIES (VIEs) (Balance Sheet Carrying Amounts Related to VIEs) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022
Variable Interest Entity [Line Items]
Pool working capital deposits		$ 39,832
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Pool working capital deposits	$ 32,521

VARIABLE INTEREST ENTITIES (V_5

VARIABLE INTEREST ENTITIES (VIEs) (Comparison of Liability to Maximum Exposure to Loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Other Liabilities	$ 2,296	$ 1,875
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	$ 32,521

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		6 Months Ended
	Jun. 02, 2022	May 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 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			$ 978,051		$ 978,051			$ 1,023,432
Net change in unrealized gains/(losses) on cash flow hedges			(3,081)	$ (966)	757	$ (11,728)
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred					8,200
Proceeds from derivative settlement		9,600
$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	750,000
$750 Million Credit Facility
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Debt instrument, face amount							$ 750,000
Derivative, notional amount	$ 475,000
Derivative, fixed interest rate	2.84%
Derivative, maturity date	Feb. 22, 2027
Long-term debt			297,078		297,078			$ 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
$390 Million Facility Term Loan and $525 Million Facility Term Loan [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred					3,400
Sinosure Credit Facility [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclosures [Line Items]
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred					(1,800)
$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		$ 750,000

FAIR VALUE OF FINANCIAL INSTR_4

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Other Than Derivatives) (Details) - USD ($)	Jun. 30, 2023	Mar. 10, 2023	Dec. 31, 2022	Jun. 02, 2022	May 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted cash	$ 0		$ 0
Debt face amount				$ 750,000,000
$390 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount					$ 390,000,000
$750 Million Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount		$ 750,000,000
$750 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	750,000,000	$ 750,000,000	750,000,000
$525 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount					$ 525,000,000
Term loan | $525 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	750,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	116,023,000		243,744,000
Short-term investments	120,000,000
Fair Value, Inputs, Level 2 [Member] | $390 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments			80,000,000
Fair Value, Inputs, Level 2 [Member] | $750 Million Facility Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(301,751,000)		(493,565,000)
Fair Value, Inputs, Level 2 [Member] | ING Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(21,875,000)		(22,917,000)
Fair Value, Inputs, Level 2 [Member] | Ocean Yield Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(326,626,000)		(341,106,000)
Fair Value, Inputs, Level 2 [Member] | BoComm Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(209,044,000)		(63,598,000)
Fair Value, Inputs, Level 2 [Member] | Toshin Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(13,877,000)		(14,744,000)
Fair Value, Inputs, Level 2 [Member] | COSCO Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(45,225,000)		(47,732,000)
Fair Value, Inputs, Level 2 [Member] | Hyuga Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(13,980,000)		(14,853,000)
Fair Value, Inputs, Level 2 [Member] | Kaiyo Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	(12,842,000)		(13,797,000)
Fair Value, Inputs, Level 2 [Member] | Kaisha Lease Financing
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	$ (12,934,000)		$ (13,704,000)

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	Jun. 30, 2023	Dec. 31, 2022
Current Portion of Derivative Assets [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 7,595	$ 6,987
Non Current Portion of Derivative Assets [Member]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	4,462	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	942	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	7,595	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	4,462	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	$ 942	$ 547

FAIR VALUE OF FINANCIAL INSTR_6

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Effect of Cash Flow Hedging Relationships) (Details) - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total other comprehensive loss	$ 5,848	$ 1,873	$ 4,393	$ 10,932
Interest Rate Swap [Member]
Total other comprehensive loss	$ 5,848	$ 1,873	$ 4,393	$ 10,932

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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	$ (2,767)	$ (907)	$ (5,150)	$ 796
Interest Expense [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	(2,767)	(907)	(5,150)	666
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	(563)	571	(1,165)	1,153
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	$ (2,204)	$ (1,478)	$ (3,985)	$ (487)

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	Jun. 30, 2023	Dec. 31, 2022
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Derivative Asset	$ 12,999	$ 12,196

DEBT (Schedule of Long-term Deb

DEBT (Schedule of Long-term Debt Instruments) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 10, 2023	Dec. 31, 2022	Jun. 02, 2022
Debt
Long-term debt	$ 978,051		$ 1,023,432
Less current portion	(199,785)		(162,854)
Long-term portion	778,266		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	4,673		6,400
$750 Million Credit Facility
Debt
Long-term debt	297,078		487,164
Debt face amount		$ 750,000
ING Credit Facility
Debt
Long-term debt	21,520		22,501
Unamortized discount and deferred finance costs	355		416
Ocean Yield Lease Financing
Debt
Long-term debt	323,702		337,908
Unamortized discount and deferred finance costs	2,924		3,198
BoComm Lease Financing
Debt
Long-term debt	236,037		71,140
Unamortized discount and deferred finance costs	4,537		917
Toshin Lease Financing
Debt
Long-term debt	14,572		15,215
Unamortized discount and deferred finance costs	333		370
COSCO Lease Financing
Debt
Long-term debt	44,165		46,544
Unamortized discount and deferred finance costs	1,060		1,187
Hyuga Lease Financing
Debt
Long-term debt	14,450		15,093
Unamortized discount and deferred finance costs	294		323
Kaiyo Lease Financing
Debt
Long-term debt	13,212		13,884
Unamortized discount and deferred finance costs	256		285
Kaisha Lease Financing
Debt
Long-term debt	13,315		13,983
Unamortized discount and deferred finance costs	$ 267		$ 298

DEBT (750 Million Credit Facili

DEBT (750 Million Credit Facility) (Details) $ in Millions	May 19, 2023 USD ($) property	Mar. 14, 2023 USD ($)	Mar. 10, 2023 USD ($) item	Mar. 09, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 02, 2022 USD ($)
Debt
Debt face amount							$ 750
$750 Million Credit Facility
Debt
Debt face amount			$ 750
Credit facility, maximum borrowing capacity			366.3
Line of Credit Facility, Remaining Borrowing Capacity			257.4
Line of credit facility, amount outstanding			0
Scheduled future quarterly principal amortization			27.7	$ 30.2
Proceeds from sale of 2008-built MR		$ 20.2
Reduction in scheduled future quarterly principal amortization		0.4
Repayment of credit facility		9.7	$ 97
Release of collateral vessel mortgages, number of MR product carriers | item			22
Additional borrowing capacity			$ 40
$750 Million Facility Term Loan
Debt
Debt face amount			$ 750		$ 750	$ 750
Scheduled future quarterly principal amortization	$ 26	$ 27.3
Repayment of credit facility	$ 28.9
Number of vessels released from collateralized mortgages | property	1

DEBT - BoComm Lease Financing R

DEBT - BoComm Lease Financing Relating to Dual-Fuel LNG VLCC Newbuilds (Details)	Nov. 15, 2021 USD ($) item
Debt Instrument [Line Items]
Sale leaseback transaction daily rate, per vehicle	$ 21,700
BoComm Lease Financing
Debt Instrument [Line Items]
Sale Leaseback Transaction, Number of Vessels | item	3
Sale Leaseback Transaction, Net Sale Price	$ 244,800,000
Sale Leaseback Transaction Net Sale Price, Per Vehicle	$ 81,600,000

DEBT (Debt Covenants) (Narrativ

DEBT (Debt Covenants) (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 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 June 30, 2023.
$750 Million Credit Facility
Debt
Debt instrument, face amount		$ 750

DEBT (Schedule of Interest Expe

DEBT (Schedule of Interest Expense and Interest Paid) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 10, 2023	Jun. 02, 2022
Debt Instrument [Line Items]
Interest expense, debt	$ 18.2	$ 13.3	$ 36.5	$ 26.6
Interest paid, net	16.9	$ 10.8	36	$ 22.6
Pre-delivery interest expenses	$ 0.7		$ 2
Debt instrument, face amount						$ 750
$750 Million Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount					$ 750

DEBT ( Debt Modification, Repur

DEBT ( Debt Modification, Repurchases and Extinguishment) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		6 Months Ended
	May 31, 2023	Mar. 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Mar. 10, 2023	Dec. 31, 2022	Jun. 02, 2022
Debt
Proceeds from Issuance of Long-term Debt			$ 0	$ 641,050
Debt instrument, face amount							$ 750,000
Gains (losses) on repurchase and extinguishment of debt			700
$750 Million Credit Facility
Debt
Debt instrument, face amount					$ 750,000
Capitalized deferred finance charges			3,300
$750 Million Facility Term Loan
Debt
Debt instrument, face amount			$ 750,000		$ 750,000	$ 750,000
Write off of deferred debt issuance cost	$ 400	$ 200

DEBT - COSCO Lease Financing (N

DEBT - COSCO Lease Financing (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	May 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt		$ 978,051		$ 1,023,432
Payments to acquire vessels		188,068	$ 53,801
COSCO Lease Financing
Debt Instrument [Line Items]
Long-term debt		$ 44,165		$ 46,544
Aframax and an LR2 | COSCO Lease Financing
Debt Instrument [Line Items]
Long-term debt	$ 45,200
Debt Related Purchase Options Premiums	1,200
Payments to acquire vessels	$ 46,400

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		6 Months Ended
	Aug. 08, 2023	May 04, 2023	Apr. 11, 2023	Feb. 27, 2023	May 08, 2022	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Aug. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments of dividends		$ 79,300		$ 98,300					$ 177,565	$ 8,941
Repurchase of common shares							62,045	26,753	121,337	84,479
Supplemental cash dividend	$ 1.30	$ 1.50		$ 1.88
Shares paid for tax withholding for share based compensation, per share amount							$ 38.52	$ 19.54	$ 46.65	$ 17.67
Stock repurchase program, authorized amount						$ 60,000	$ 60,000		$ 60,000		$ 50,000
Dividends payable, date declared		May 04, 2023		Feb. 27, 2023
Dividends payable, amount per share		$ 0.12		$ 0.12
Dividends payable, date of record	Sep. 13, 2023
Dividends payable, date to be paid	Sep. 27, 2023	Jun. 28, 2023		Mar. 28, 2023
Stock Repurchased and Retired During Period, Value							$ 13,900
Stock Repurchased and Retired During Period, Shares							366,483			0
Stock repurchased per share amount							$ 38.03
Stock repurchase program, remaining authorized repurchase amount						$ 26,100	$ 26,100		$ 26,100
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%		17.50%
Purchase Price			$ 50		$ 25
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends payable, date declared	Aug. 08, 2023
Dividends payable, amount per share	$ 0.12
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
Restricted Stock | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						26,878
Granted, per share						$ 37.94
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	6 Months Ended
	Jun. 30, 2023 USD ($)
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred	$ 8.2

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
ACCUMULATED OTHER COMPREHENSIVE INCOME [Abstract]
Unrealized gains on derivative instruments	$ 16,155	$ 16,912
Items not yet recognized as a component of net periodic benefit cost (pension plans)	(10,400)	(9,948)
Accumulated other comprehensive loss	$ 5,755	$ 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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Balance, beginning	$ 1,557,283	$ 1,165,450	$ 1,487,752	$ 1,170,332
Other comprehensive income/(loss), net of tax	2,853	1,528	(1,209)	12,487
Balance, ending	1,620,274	1,231,148	1,620,274	1,231,148
Accumulated Other Comprehensive Loss [Member]
Balance, beginning	2,902	(1,401)	6,964	(12,360)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	5,620	2,435	3,941	11,691
Amounts reclassified from accumulated other comprehensive income/(loss)	(2,767)	(907)	(5,150)	796
Other comprehensive income/(loss), net of tax	2,853	1,528	(1,209)	12,487
Balance, ending	5,755	127	5,755	127
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance, beginning	13,074	5,899	16,912	(4,863)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	5,848	1,873	4,393	10,932
Amounts reclassified from accumulated other comprehensive income/(loss)	(2,767)	(907)	(5,150)	796
Balance, ending	16,155	6,865	16,155	6,865
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance, beginning	(10,172)	(7,300)	(9,948)	(7,497)
Current period change, excluding amounts reclassified from accumulated other comprehensive income/(loss)	(228)	562	(452)	759
Balance, ending	$ (10,400)	$ (6,738)	$ (10,400)	$ (6,738)

ACCUMULATED OTHER COMPREHENSI_6

ACCUMULATED OTHER COMPREHENSIVE INCOME (Amounts Reclassified out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Unrealized losses on available-for-sale securities:
Equity in income of affiliated companies	$ 154,143	$ 69,088	$ 326,775	$ 56,091
Income (loss) from equity method investments		(5,162)	0	435
Interest expense	17,914	12,558	34,861	25,298
Other income	3,381	(574)	7,662	(800)
Total reclassified out of AOCL, before tax	(2,767)	(907)	(5,150)	796
Interest Rate Cap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Unrealized losses on available-for-sale securities:
Interest expense	(563)	571	(1,165)	1,153
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	$ (2,204)	$ (1,478)	$ (3,985)	$ (487)

REVENUE (Narrative) (Details)

REVENUE (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) property	Jun. 30, 2022 USD ($)
Revenues, Total | $	$ 292,203,000	$ 188,197,000	$ 579,333,000	$ 289,679,000
Capitalized contract cost, gross | $	$ 0		$ 0
Lease cancellation period notice			90 days
Very Large Crude Carrier [Member]
Number of vessels party to contracts | property			4
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 | $			4

REVENUE (Schedule of Disaggrega

REVENUE (Schedule of Disaggregated Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue, non lease	$ 292,203	$ 188,197	$ 579,333	$ 289,679
Shipping revenues	292,203	188,197	579,333	289,679
Loss of hire proceeds		900
International Crude Tankers Segment [Member]
Revenue, non lease	152,168	62,107	284,579	101,717
Shipping revenues	152,168	62,107	284,579	101,717
International Product Carriers Segment [Member]
Revenue, non lease	140,035	126,090	294,754	187,962
Shipping revenues	140,035	126,090	294,754	187,962
Other Segments [Member]
Revenue, non lease	0	0
Pool Revenue Leases [Member]
Shipping revenues	247,591	164,727	507,169	248,489
Pool Revenue Leases [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	$ 247,591	$ 164,727	$ 507,169	$ 248,489
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Shipping revenues	Shipping revenues	Shipping revenues	Shipping revenues
Pool Revenue Leases [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	$ 119,639	$ 45,166	$ 228,438	$ 72,476
Pool Revenue Leases [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	127,952	119,561	278,731	176,013
Voyage Charter Leases Non Variable Payments [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	5,958	6,830	8,522	12,721
Voyage Charter Leases Non Variable Payments [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	1,417	2,237	3,655	5,081
Voyage Charter Leases Non Variable Payments [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, lease non-variable	4,541	4,593	4,867	7,640
Voyage Charter Leases Variable Payments [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases	66	55	216	(9)
Voyage Charter Leases Variable Payments [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases	66	48	66	62
Voyage Charter Leases Variable Payments [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue (expense), operating leases		7	150	(71)
Time and Bareboat Charter Leases [Member]
Shipping revenues	26,112	8,133	39,262	14,308
Time and Bareboat Charter Leases [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	$ 26,112	$ 8,133	$ 39,262	$ 14,308
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Shipping revenues	Shipping revenues	Shipping revenues	Shipping revenues
Time and Bareboat Charter Leases [Member] | International Crude Tankers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	$ 18,570	$ 6,204	$ 28,256	$ 9,928
Time and Bareboat Charter Leases [Member] | International Product Carriers Segment [Member] | Fixed-Price Contract [Member]
Revenue, operating leases	7,542	1,929	11,006	4,380
Voyage Charter Leases [Member]
Shipping revenues	18,500	15,337	32,902	26,882
Voyage Charter Leases [Member] | Lightering Services Component [Member]
Revenue, non lease	12,476	8,452	24,164	14,170
Voyage Charter Leases [Member] | International Crude Tankers Segment [Member] | Lightering Services Component [Member]
Revenue, non lease	$ 12,476	$ 8,452	$ 24,164	$ 14,170

REVENUE (Schedule of Contract R

REVENUE (Schedule of Contract Related Receivables, Assets and Liabilities with Customers) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
REVENUE [Abstract]
Voyage receivables - receivables	$ 2,887	$ 9,452
Contract asset (voyage receivables unbilled receivables)	3,536	1,866
Contract liability (deferred revenues)	$ 0	$ 0

LEASES (Narrative) (Details)

LEASES (Narrative) (Details)	1 Months Ended	6 Months Ended
	Dec. 31, 2022 USD ($)	Jun. 30, 2023 USD ($) lease
Leases [Line Items]
Number of major categories of leases | lease		2
MR Vessel [Member]
Leases [Line Items]
Number of vessels chartered		4
Aframaxes [Member]
Leases [Line Items]
Number of vessels chartered		1
LR2 Vessel [Member]
Leases [Line Items]
Number of vessels chartered		1
Very Large Crude Carrier [Member]
Leases [Line Items]
Number of vessels chartered		4
Suezmax
Leases [Line Items]
Number of vessels chartered		2
Two 2009 Aframaxes Vessels [Member]
Leases [Line Items]
Payments to acquire equipment	$ 43,000,000
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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating lease, cost	$ 10,502	$ 7,693	$ 19,302	$ 15,002
Total lease cost	6,124	4,285	12,569	8,452
Vessel/Fleet [Member] | Charter Hire Expense [Member]
Operating lease, cost	678	2,481	1,745	4,899
Short-term lease, cost	5,154	1,533	9,423	3,012
Vessel/Fleet [Member] | Vessel Expense [Member]
Amortization of right-of-use assets	16		731	0
Interest on lease liabilities	3		124	0
Office Space [Member] | General and Administrative Expense [Member]
Operating lease, cost	228	228	456	455
Office Space [Member] | Voyage Expense [Member]
Operating lease, cost	45	43	90	86
Lightering Services Component [Member] | Vessel/Fleet [Member]
Short-term lease, cost	$ 1,600	$ 700	$ 1,700	$ 1,100

LEASES (Supplemental lease info

LEASES (Supplemental lease information) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows used for operating leases	$ 1,685	$ 5,035
Finance cash flows used for finance leases	42,284	$ 0
Current portion of operating lease liabilities	(452)		$ (1,596)
Operating Lease, Liability, Noncurrent	7,539		7,740
Operating Lease, Right-of-Use Asset	6,308		8,471
Finance lease right-of-use assets	0		44,391
Current portion of finance lease liabilities	0		(41,870)
Total operating and finance lease liabilities	$ 7,991		$ 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	4.44%		4.13%
Lessee, Finance Lease, Remaining Lease Term			2 months 12 days
Lessee, Finance Lease, Discount Rate			4.78%

LEASES (Bareboat and Time Chart

LEASES (Bareboat and Time Charters-In) (Details) - Time Charters-In [Member] $ in Thousands	Jun. 30, 2023 USD ($)
Leases [Line Items]
2023	$ 5,937
2024	12,627
2025	$ 5,624

LEASES (Future Minimum Lease Ob

LEASES (Future Minimum Lease Obligations for Office Space) (Details) - Office Space And Lightering Workboat Dock Space [Member] $ in Thousands	Jun. 30, 2023 USD ($)
Leases [Line Items]
2023	$ (105)
2024	1,167
2025	998
2026	1,024
2027	1,077
Thereafter	5,831
Total lease payments	9,992
less imputed interest	(2,001)
Total operating lease liabilities	$ 7,991

LEASES (Future Minimum Revenues

LEASES (Future Minimum Revenues on Charters-Out) (Details) - Charters-Out [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Operating Leases, Future Minimum Payments Receivable [Abstract]
2023	$ 50,500
2024	91,515
2025	58,926
2026	42,098
2027	33,945
Thereafter	75,051
Net minimum lease payments	$ 352,035
2023, revenue days	1764 days
2024, revenue days	3152 days
2025, revenue days	1922 days
2026, revenue days	1336 days
2027, revenue days	1095 days
Thereafter	2421 days
Revenue Days	11690 days

CONTINGENCIES (Narrative) (Deta

CONTINGENCIES (Narrative) (Details)	6 Months Ended
	Jun. 30, 2023
Merchant Navy Ratings Pension Fund [Member]
Loss Contingencies [Line Items]
Multiemployer period of performance in the past	20 years

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 153,762	$ 69,036	$ 326,395	$ 56,035

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2023 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Jeffrey Pribor
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On June 6, 2023, Mr. Jeffrey Pribor, the Company’s Chief Financial Officer, Senior Vice President and Treasurer, entered into a trading plan designed to satisfy the affirmative defense of Rule 10b5-1(c) under the Securities Exchange act of 1934, as amended (the “Plan”). The Plan provides for sale of up to 12,000 shares of our Common Stock beginning on October 2, 2023 until December 31, 2024 or when all of the shares have been sold. The Plan was adopted in accordance with our insider trading policy. Actual sale transactions will be disclosed publicly in filings with the SEC in accordance with applicable securities laws, rules and regulations.
Name	Mr. Jeffrey Pribor
Title	Chief Financial Officer, Senior Vice President and Treasurer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	June 6, 2023
Aggregate Available	12,000
Expiration Date	December 31, 2024