Altice USA (ATUS) 10-Q 28 Apr 21 2021 FY Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 19, 2021
Document and Entity Information [Abstract]
Title of 12(b) Security	Class A Common Stock, par value $0.01 per share
Entity Interactive Data Current	Yes
Entity File Number	001-38126
Document Transition Report	false
Document Type	10-Q
Entity Central Index Key	0001702780
Entity Registrant Name	Altice USA, Inc.
Document Fiscal Year Focus	2021
Entity Filer Category	Large Accelerated Filer
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Period End Date	Mar. 31, 2021
Entity Common Stock, Shares Outstanding		459,814,587
Entity Current Reporting Status	Yes
Entity Small Business	false
Current Fiscal Year End Date	--12-31
Entity Tax Identification Number	38-3980194
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1 Court Square West
Entity Address, City or Town	Long Island City,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	11101
City Area Code	(516)
Local Phone Number	803-2300
Trading Symbol	ATUS
Security Exchange Name	NYSE
Document Quarterly Report	true

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 220,571	$ 278,422
Restricted cash	264	264
Accounts receivable, trade (less allowance for doubtful accounts of $22,395 and $25,198)	376,155	442,581
Prepaid expenses and other current assets	221,819	200,252
Amounts due from affiliates	3,795	4,262
Derivative contracts	8,252	50,785
Total current assets	830,856	976,566
Property, plant and equipment, net of accumulated depreciation of $6,639,771 and $6,431,843	5,843,572	5,805,996
Right-of-use operating lease assets	234,358	241,342
Investment securities pledged as collateral		2,250,854
Derivative contracts	0	4,774
Other assets	92,137	87,429
Amortizable intangibles, net of accumulated amortization of $4,574,426 and $4,409,312	2,616,017	2,781,116
Indefinite-lived cable television franchises	13,068,017	13,068,017
Goodwill	8,160,566	8,160,566
Total assets	33,169,831	33,376,660
Current Liabilities:
Accounts payable	879,032	795,576
Interest payable	233,968	252,060
Accrued employee related costs	104,220	142,116
Amounts due to affiliates	12,698	8,538
Deferred revenue	153,032	109,798
Debt	1,258,055	1,245,713
Other current liabilities	550,263	544,302
Total current liabilities	3,191,268	3,098,103
Other liabilities	172,766	192,563
Deferred tax liability	5,037,625	5,006,167
Liabilities under derivative contracts	472,402	523,150
Right-of-use operating lease liability	248,758	257,424
Long-term debt, net of current maturities	25,431,481	25,476,629
Total liabilities	34,554,300	34,554,036
Commitments and contingencies (Note 16)
Redeemable equity	3,104	25,763
Stockholders' Deficiency:
Preferred stock, $0.01 par value, 100,000,000 shares authorized, no shares issued and outstanding	0	0
Paid-in capital	0	0
Accumulated deficit	(1,185,610)	(985,641)
Total stockholders' equity before accumulated other comprehensive Income and non-controlling interest	(1,180,930)	(980,810)
Treasury stock, at cost (6,066,251 and 6,629,415 Class A common shares at March 31, 2021 and December 31, 2020, respectively)	163,860	163,866
Accumulated other comprehensive income	10,621	3,646
Total Altice USA stockholders' deficiency	(1,334,169)	(1,141,030)
Noncontrolling interests	(53,404)	(62,109)
Total stockholders' deficiency	(1,387,573)	(1,203,139)
Total liabilities and stockholders' deficiency	33,169,831	33,376,660
Common Class A
Stockholders' Deficiency:
Common stock	2,822	2,972
Common Class B
Stockholders' Deficiency:
Common stock	1,858	1,859
Common Class C
Stockholders' Deficiency:
Common stock	0	0
CSC Holdings
Current Assets:
Cash and cash equivalents	220,214	277,938
Restricted cash	264	264
Accounts receivable, trade (less allowance for doubtful accounts of $22,395 and $25,198)	376,155	442,581
Prepaid expenses and other current assets	221,819	200,252
Amounts due from affiliates	3,795	4,262
Derivative contracts	8,252	50,785
Total current assets	830,499	976,082
Property, plant and equipment, net of accumulated depreciation of $6,639,771 and $6,431,843	5,843,572	5,805,996
Right-of-use operating lease assets	234,358	241,342
Investment securities pledged as collateral	2,324,308	2,250,854
Derivative contracts	0	4,774
Other assets	92,137	87,429
Amortizable intangibles, net of accumulated amortization of $4,574,426 and $4,409,312	2,616,017	2,781,116
Indefinite-lived cable television franchises	13,068,017	13,068,017
Goodwill	8,160,566	8,160,566
Total assets	33,169,474	33,376,176
Current Liabilities:
Accounts payable	879,032	795,576
Interest payable	233,968	252,060
Accrued employee related costs	104,220	142,116
Amounts due to affiliates	12,698	8,538
Deferred revenue	153,032	109,798
Debt	1,258,055	1,245,713
Other current liabilities	530,853	543,834
Total current liabilities	3,171,858	3,097,635
Other liabilities	172,766	192,563
Deferred tax liability	5,065,438	5,033,980
Liabilities under derivative contracts	472,402	523,150
Right-of-use operating lease liability		257,424
Long-term debt, net of current maturities	25,431,481	25,476,629
Total liabilities	34,562,703	34,581,381
Redeemable equity	3,104	25,763
Stockholders' Deficiency:
Accumulated other comprehensive income	10,621	3,646
Noncontrolling interests	(53,404)	(62,109)
Total liabilities and stockholders' deficiency	$ 33,169,474	$ 33,376,176

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Assets [Abstract]
Property, plant and equipment, accumulated depreciation	$ 6,639,771	$ 6,431,843
Amortizable intangible assets, accumulated amortization	$ 4,574,426	4,409,312
Accounts receivable, trade allowance for doubtful accounts		$ 25,198
Stockholders' Deficiency:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury Stock, Shares, Acquired	6,066,251	6,629,415
Common stock, shares outstanding (in shares)	461,977,407
Common Class A
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	4,000,000,000	4,000,000,000
Common stock, shares issued (in shares)	282,245,265	297,203,087
Common stock, shares outstanding (in shares)	276,179,014	290,573,672
Common Class B
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares outstanding (in shares)	185,798,393	185,895,903
Common Class C
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	4,000,000,000	4,000,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue (including revenue from affiliates of $3,406 and $3,488 respectively) (See Note 15)	$ 2,478,821	$ 2,450,256
Operating expenses:
Programming and other direct costs (including charges from affiliates of $2,228 and $2,189 respectively) (See Note 15)	851,864	864,514
Other operating expenses (including charges from affiliates of $3,179 and $3,941 respectively) (See Note 15)	580,433	582,309
Restructuring and other expense	3,209	7,294
Depreciation and amortization (including impairments)	434,857	547,569
Total operating expenses	1,870,363	2,001,686
Operating income	608,458	448,570
Other income (expense):
Interest expense	(316,339)	(365,211)
Interest income	27	1,659
Gain (loss) on investments and sale of affiliate interests, net	73,453	(455,473)
Gain (loss) on derivative contracts related to change in the value of equity derivative contracts related to Comcast common stock	(53,565)	439,861
Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below	75,653	(54,832)
Other income, net	2,859	923
Total other income (expense)	(217,912)	(433,073)
Income before income taxes	390,546	15,497
Income Tax Expense (Benefit)	(112,007)	(17,035)
Net income (loss)	278,539	(1,538)
Net loss (income) attributable to noncontrolling interests	(4,403)	680
Net income (loss) attributable to Altice USA, Inc. stockholders	$ 274,136	$ (858)
Income (loss) per share:
Basic income (loss) per share	$ 0.58	$ 0
Basic weighted average common shares (in thousands)	469,233	621,414
Diluted income (loss) per share	$ 0.58	$ 0
Diluted weighted average common shares (in thousands)	475,448	621,414
Cash dividends declared per common share	$ 0	$ 0

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue from affiliates	$ 3,406	$ 3,488
Programming and other direct costs from affiliates	2,228	2,189
Other operating expenses from affiliates	$ 3,179	$ 3,941

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 278,539	$ (1,538)
Defined benefit pension plans:
Unrecognized actuarial gain (loss)		(13,469)
Applicable income taxes		3,598
Unrecognized gain (loss) arising during period, net of income taxes	6,906	(9,871)
Settlement loss (gain) included in other expense, net		502
Applicable income taxes		(134)
Settlement loss (gain) included in other expense, net, net of income taxes	(550)	368
Foreign currency translation adjustment		(424)
Applicable income taxes		0
Foreign currency translation adjustment, net	619	(424)
Other comprehensive income (loss)	6,975	(9,927)
Comprehensive income (loss)	285,514	(11,465)
Comprehensive loss (income) attributable to noncontrolling interests		680
Comprehensive income (loss) attributable to Altice USA, Inc. stockholders	$ 281,111	$ (10,785)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Parent [Member]	Member's Equity (Deficiency)	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income	Noncontrolling Interests	Common Class ACommon Stock	Common Class BCommon Stock
Beginning balance at Dec. 31, 2019	$ 2,279,262	$ 2,269,964	$ 2,039,918		$ (163,904)	$ (3,250)	$ 9,298	$ 4,572	$ 1,862
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Altice USA, Inc. stockholders	(858)			$ (858)				(858)	0
Net loss (income) attributable to noncontrolling interests	680						680
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Net Of Tax	9,503	9,503				9,503
Foreign currency translation adjustment, net	(424)	(424)				(424)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	27,370	27,370	27,370
Redeemable equity vested	29,479	29,479	29,479
Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock	13,260	13,260	13,260
Class A shares acquired through share repurchase program and retired	(749,998)	(749,998)	(749,686)					(312)
Stock Issued During Period, Value, New Issues	2,507	2,507			11
Other							4,302
Ending balance at Mar. 31, 2020	1,590,415	1,581,797	1,362,836		(163,893)	(13,177)	8,618	4,261	1,862
Beginning balance at Dec. 31, 2020	(1,203,139)	(1,141,030)	0	(985,641)	(163,866)	3,646	(62,109)	2,972	1,859
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Altice USA, Inc. stockholders	274,136	274,136		274,136
Net loss (income) attributable to noncontrolling interests	(4,403)						(4,403)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Net Of Tax	(6,356)	(6,356)				6,356
Foreign currency translation adjustment, net	619	619				619
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	27,964	27,964		27,964
Redeemable equity vested	20,131	20,131		20,131
Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock	2,528	2,528		2,528
Class A shares acquired through share repurchase program and retired	(522,673)	(522,673)		(522,521)				(152)
Conversion of Class B to Class A shares								1	(1)
Stock Issued During Period, Value, New Issues	2,044	2,044	2,495	2,037	6			1
Other	58	(4,244)	0	(4,244)
Ending balance at Mar. 31, 2021	$ (1,387,573)	$ (1,334,169)	$ 0	$ (1,185,610)	$ (163,860)	$ 10,621	$ (53,404)	$ 2,822	$ 1,858

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income (loss)	$ 278,539	$ (1,538)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization (including impairments)	434,857	547,569
Loss (gain) on investments and sale of affiliate interests, net	(73,453)	455,473
Gain (Loss) on Price Risk Derivative Instruments Not Designated as Hedging Instruments	53,565	(439,861)
Amortization of deferred financing costs and discounts (premiums) on indebtedness	23,039	23,944
Share-based compensation expense	28,281	27,946
Deferred income taxes	29,165	30,225
Decrease in right-of-use assets	10,816	11,474
Provision for doubtful accounts	11,133	19,880
Other	1,074	1,849
Change in assets and liabilities, net of effects of acquisitions and dispositions:
Accounts receivable, trade	55,293	(4,458)
Prepaid expenses and other assets	(26,321)	(34,800)
Amounts due from and due to affiliates	4,627	3,894
Accounts payable and accrued liabilities	(29,696)	(165,728)
Deferred revenue	38,501	(5,153)
Liabilities related to interest rate swap contracts	(89,798)	122,849
Net cash provided by operating activities	749,622	593,565
Cash flows from investing activities:
Capital expenditures	(212,791)	(299,082)
Other, net	2,143	1,339
Net cash used in investing activities	(210,648)	(297,743)
Cash flows from financing activities:
Proceeds from long-term debt	150,000	0
Repayment of long-term debt	(225,863)	(18,183)
Proceeds from collateralized indebtedness and related derivative contracts, net	185,105	0
Repayment of collateralized indebtedness and related derivative contracts, net	(185,105)	0
Principal payments on finance lease obligations	(18,330)	(5,700)
Purchase of shares of Altice USA Class A common stock, pursuant to a share repurchase program	(503,645)	(726,005)
Other	(393)	2,915
Net cash used in financing activities	(597,445)	(752,803)
Net decrease in cash and cash equivalents	(58,471)	(456,981)
Effect of exchange rate changes on cash and cash equivalents	620	(424)
Net decrease in cash and cash equivalents	(57,851)	(457,405)
Cash, cash equivalents and restricted cash at beginning of year	278,686	702,160
Cash, cash equivalents and restricted cash at end of period	$ 220,835	$ 244,755

CSC HOLDINGS - CONSOLIDATED BAL

CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 220,571	$ 278,422
Restricted cash	264	264
Accounts receivable, trade (less allowance for doubtful accounts of $13,420 and $11,677)	376,155	442,581
Prepaid expenses and other current assets (including a prepayment to an affiliate of $19,563 in 2017) (See Note 14)	221,819	200,252
Amounts due from affiliates	3,795	4,262
Derivative contracts	8,252	50,785
Total current assets	830,856	976,566
Property, plant and equipment, net	5,843,572	5,805,996
Right-of-use operating lease assets	234,358	241,342
Investment securities pledged as collateral		2,250,854
Derivative contracts	0	4,774
Other assets	92,137	87,429
Amortizable intangible assets, net of accumulated amortization	2,616,017	2,781,116
Indefinite-lived cable television franchises	13,068,017	13,068,017
Goodwill	8,160,566	8,160,566
Total assets	33,169,831	33,376,660
Current Liabilities:
Accounts payable	879,032	795,576
Interest payable	233,968	252,060
Accrued employee related costs	104,220	142,116
Amounts due to affiliates	12,698	8,538
Deferred revenue	153,032	109,798
Debt	1,258,055	1,245,713
Other current liabilities	550,263	544,302
Total current liabilities	3,191,268	3,098,103
Other liabilities	172,766	192,563
Deferred tax liability	5,037,625	5,006,167
Liabilities under derivative contracts	472,402	523,150
Right-of-use operating lease liability	248,758	257,424
Long-term debt, net of current maturities	25,431,481	25,476,629
Total liabilities	34,554,300	34,554,036
Commitments and contingencies (Note 16)
Redeemable equity	3,104	25,763
Limited Liability Company (LLC) Members' Equity [Abstract]
Accumulated other comprehensive income (loss)	10,621	3,646
Noncontrolling interests	(53,404)	(62,109)
Total liabilities and stockholders' deficiency	33,169,831	33,376,660
Customer Relationships [Member]
Current Assets:
Amortizable intangible assets, net of accumulated amortization	2,433,901	2,573,856
Other Intangible Assets [Member]
Current Assets:
Amortizable intangible assets, net of accumulated amortization	18,853	20,366
CSC Holdings
Current Assets:
Cash and cash equivalents	220,214	277,938
Restricted cash	264	264
Accounts receivable, trade (less allowance for doubtful accounts of $13,420 and $11,677)	376,155	442,581
Prepaid expenses and other current assets (including a prepayment to an affiliate of $19,563 in 2017) (See Note 14)	221,819	200,252
Amounts due from affiliates	3,795	4,262
Derivative contracts	8,252	50,785
Total current assets	830,499	976,082
Property, plant and equipment, net	5,843,572	5,805,996
Right-of-use operating lease assets	234,358	241,342
Investment securities pledged as collateral	2,324,308	2,250,854
Derivative contracts	0	4,774
Other assets	92,137	87,429
Amortizable intangible assets, net of accumulated amortization	2,616,017	2,781,116
Indefinite-lived cable television franchises	13,068,017	13,068,017
Goodwill	8,160,566	8,160,566
Total assets	33,169,474	33,376,176
Current Liabilities:
Accounts payable	879,032	795,576
Interest payable	233,968	252,060
Accrued employee related costs	104,220	142,116
Amounts due to affiliates	12,698	8,538
Deferred revenue	153,032	109,798
Debt	1,258,055	1,245,713
Other current liabilities	530,853	543,834
Total current liabilities	3,171,858	3,097,635
Other liabilities	172,766	192,563
Deferred tax liability	5,065,438	5,033,980
Liabilities under derivative contracts	472,402	523,150
Right-of-use operating lease liability		257,424
Long-term debt, net of current maturities	25,431,481	25,476,629
Total liabilities	34,562,703	34,581,381
Redeemable equity	3,104	25,763
Limited Liability Company (LLC) Members' Equity [Abstract]
Membership interest before accumulated comprehensive loss	(1,353,550)	(1,172,505)
Accumulated other comprehensive income (loss)	10,621	3,646
Membership equity before noncontrolling interest	(1,342,929)	(1,168,859)
Noncontrolling interests	(53,404)	(62,109)
Total Equity (Deficiency)	(1,396,333)	(1,230,968)
Total liabilities and stockholders' deficiency	$ 33,169,474	$ 33,376,176

CSC HOLDINGS - CONSOLIDATED B_2

CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounts receivable, trade allowance for doubtful accounts		$ 25,198
Property, plant and equipment, accumulated depreciation	$ 6,639,771	6,431,843
Amortizable intangible assets, accumulated amortization	4,574,426	4,409,312
CSC Holdings
Accounts receivable, trade allowance for doubtful accounts	22,395	25,198
Property, plant and equipment, accumulated depreciation	6,639,771	6,431,843
Amortizable intangible assets, accumulated amortization	$ 4,574,426	$ 4,409,312
Members' Equity	100	100
Common Unit, Outstanding	100	100

CSC HOLDINGS - CONSOLIDATED STA

CSC HOLDINGS - CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue (including revenue from affiliates of $3,406 and $3,488 respectively) (See Note 15)	$ 2,478,821	$ 2,450,256
Operating expenses:
Programming and other direct costs (including charges from affiliates of $2,228 and $2,189 respectively) (See Note 15)	851,864	864,514
Other operating expenses (including charges from affiliates of $3,179 and $3,941 respectively) (See Note 15)	580,433	582,309
Restructuring and other expense	3,209	7,294
Depreciation and amortization (including impairments)	434,857	547,569
Total operating expenses	1,870,363	2,001,686
Operating income	608,458	448,570
Other income (expense):
Interest expense	(316,339)	(365,211)
Interest income	27	1,659
Gain (loss) on investments and sale of affiliate interests, net	73,453	(455,473)
Loss on equity derivative contracts, net	(53,565)	439,861
Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below	75,653	(54,832)
Other income, net	2,859	923
Total other income (expense)	(217,912)	(433,073)
Income before income taxes	390,546	15,497
Income Tax Expense (Benefit)	(112,007)	(17,035)
Net income	278,539	(1,538)
Net loss (income) attributable to noncontrolling interests	(4,403)	680
Net income attributable to CSC Holdings, LLC sole member	274,136	(858)
CSC Holdings
Revenue (including revenue from affiliates of $3,406 and $3,488 respectively) (See Note 15)	2,478,821	2,450,256
Operating expenses:
Programming and other direct costs (including charges from affiliates of $2,228 and $2,189 respectively) (See Note 15)	851,864	864,514
Other operating expenses (including charges from affiliates of $3,179 and $3,941 respectively) (See Note 15)	580,433	582,309
Restructuring and other expense	3,209	7,294
Depreciation and amortization (including impairments)	434,857	547,569
Total operating expenses	1,870,363	2,001,686
Operating income	608,458	448,570
Other income (expense):
Interest expense	(316,339)	(365,211)
Interest income	27	1,659
Gain (loss) on investments and sale of affiliate interests, net	73,453	(455,819)
Loss on equity derivative contracts, net	(53,565)	439,861
Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below	75,653	(54,832)
Other income, net	2,859	923
Total other income (expense)	(217,912)	(433,419)
Income before income taxes	390,546	15,151
Income Tax Expense (Benefit)	(112,007)	(5,029)
Net income	278,539	10,122
Net loss (income) attributable to noncontrolling interests	(4,403)	680
Net income attributable to CSC Holdings, LLC sole member	$ 274,136	$ 10,802

CSC HOLDINGS - CONSOLIDATED S_2

CSC HOLDINGS - CONSOLIDATED STATEMENT OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue from affiliates	$ 3,406	$ 3,488
Programming and other direct costs from affiliates	2,228	2,189
Related Party Transaction, Other Operating Expense	$ 3,179	$ 3,941

CSC HOLDINGS - CONDENSED CONSOL

CSC HOLDINGS - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net income	$ 278,539	$ (1,538)
Defined benefit pension and postretirement plans:
Unrecognized actuarial gain (loss)		(13,469)
Applicable income taxes		3,598
Unrecognized gain (loss) arising during period, net of income taxes	6,906	(9,871)
Settlement loss (gain) included in other expense, net		502
Applicable income taxes		(134)
Settlement loss (gain) included in other expense, net, net of income taxes	(550)	368
Foreign currency translation adjustment		(424)
Applicable income taxes		0
Foreign currency translation adjustment, net	619	(424)
Other comprehensive income (loss)	6,975	(9,927)
Comprehensive income (loss)	285,514	(11,465)
Comprehensive loss (income) attributable to noncontrolling interests		680
Comprehensive income (loss) attributable to Altice USA, Inc. stockholders	281,111	(10,785)
CSC Holdings
Net income	278,539	10,122
Defined benefit pension and postretirement plans:
Unrecognized actuarial gain (loss)	9,396	(13,469)
Applicable income taxes	(2,490)	3,598
Unrecognized gain (loss) arising during period, net of income taxes	6,906	(9,871)
Settlement loss (gain) included in other expense, net	(748)	502
Applicable income taxes	198	(134)
Settlement loss (gain) included in other expense, net, net of income taxes	(550)	368
Foreign currency translation adjustment	619	(424)
Applicable income taxes	0
Foreign currency translation adjustment, net	619	(424)
Other comprehensive income (loss)	6,975	(9,927)
Comprehensive income (loss)	285,514	195
Comprehensive loss (income) attributable to noncontrolling interests	(4,403)	680
Comprehensive income (loss) attributable to Altice USA, Inc. stockholders	$ 281,111	$ 875

CSC HOLDINGS - CONSOLIDATED S_3

CSC HOLDINGS - CONSOLIDATED STATEMENT OF MEMBER'S EQUITY - USD ($) $ in Thousands	Total	CSC Holdings	Total Member's Equity (Deficiency)	Total Member's Equity (Deficiency)CSC Holdings	Noncontrolling Interests	Noncontrolling InterestsCSC Holdings	Member's Equity (Deficiency)	Member's Equity (Deficiency)CSC Holdings	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)CSC Holdings
Accumulated deficit									$ 390,766
Member's Equity (Deficiency)								$ 2,047,397
Accumulated other comprehensive income											$ (3,250)
Membership equity before noncontrolling interest				$ 2,044,147
Noncontrolling interests		$ 9,298
Total Equity (Deficiency)		2,053,445
Net income attributable to CSC Holdings, LLC sole member	$ (858)	10,802		10,802				10,802	(858)
Net Income (Loss) Attributable to Noncontrolling Interest	(680)	(680)			$ (680)	$ (680)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Net Of Tax	(9,503)	(9,503)	$ (9,503)	(9,503)						$ (9,503)	(9,503)
Foreign currency translation adjustment, net	(424)	(424)	(424)	(424)						(424)	(424)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	27,370	27,370	27,370	27,370			$ 27,370	27,370
Redeemable equity vested	29,479	29,479	29,479	29,479			29,479	29,479
Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock	(13,260)	(13,260)	(13,260)	(13,260)			$ (13,260)	(13,260)
Cash distributions to parent		720,350		720,350				720,350
Intercompany settlement		(150,602)		(150,602)				(150,602)
Distributions to parent	150,602
Accumulated deficit									389,908
Member's Equity (Deficiency)								1,257,356
Accumulated other comprehensive income											(13,177)
Membership equity before noncontrolling interest				1,244,179
Noncontrolling interests		8,618				8,618
Total Equity (Deficiency)		1,252,797
Accumulated deficit	(985,641)
Member's Equity (Deficiency)								(1,172,505)
Accumulated other comprehensive income	3,646	3,646									3,646
Membership equity before noncontrolling interest		(1,168,859)		(1,168,859)
Noncontrolling interests	(62,109)	(62,109)				(62,109)
Total Equity (Deficiency)		(1,230,968)
Net income attributable to CSC Holdings, LLC sole member	274,136	274,136	274,136	274,136				274,136	274,136
Net Income (Loss) Attributable to Noncontrolling Interest	4,403	4,403			$ 4,403	4,403
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Net Of Tax	6,356	6,356	6,356	6,356						(6,356)	6,356
Foreign currency translation adjustment, net	619	619	619	619						$ 619	619
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	27,964	27,964	27,964	27,964				27,964	27,964
Redeemable equity vested	20,131	20,131	20,131	20,131				20,131	20,131
Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock	(2,528)	(2,528)	$ (2,528)	(2,528)				(2,528)	$ (2,528)
Cash distributions to parent		501,000		501,000				501,000
Intercompany settlement		745
Distributions to parent	745
Stockholders' Equity, Other		(502)		(4,804)		4,302		(4,804)
Accumulated deficit	(1,185,610)
Member's Equity (Deficiency)								$ (1,353,550)
Accumulated other comprehensive income	10,621	10,621									$ 10,621
Membership equity before noncontrolling interest		(1,342,929)		$ (1,342,929)
Noncontrolling interests	$ (53,404)	(53,404)				$ (53,404)
Total Equity (Deficiency)		$ (1,396,333)

CSC HOLDINGS - CONSOLIDATED S_4

CSC HOLDINGS - CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 278,539	$ (1,538)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization (including impairments)	434,857	547,569
Loss (gain) on investments and sale of affiliate interests, net	(73,453)	455,473
Loss (gain) on derivative contracts, net	53,565	(439,861)
Amortization of deferred financing costs and discounts (premiums) on indebtedness	23,039	23,944
Share-based compensation expense	28,281	27,946
Deferred income taxes	29,165	30,225
Decrease in right-of-use assets	10,816	11,474
Provision for doubtful accounts	11,133	19,880
Other	1,074	1,849
Change in assets and liabilities, net of effects of acquisitions and dispositions:
Accounts receivable, trade	55,293	(4,458)
Prepaid expenses and other assets	(26,321)	(34,800)
Amounts due from and due to affiliates	4,627	3,894
Accounts payable and accrued liabilities	(29,696)	(165,728)
Deferred revenue	38,501	(5,153)
Liabilities related to interest rate swap contracts	(89,798)	122,849
Net cash provided by operating activities	749,622	593,565
Cash flows from investing activities:
Capital expenditures	(212,791)	(299,082)
Other, net	2,143	1,339
Net cash used in investing activities	(210,648)	(297,743)
Cash flows from financing activities:
Proceeds from long-term debt	150,000	0
Repayment of long-term debt	(225,863)	(18,183)
Proceeds from collateralized indebtedness and related derivative contracts, net	185,105	0
Repayment of collateralized indebtedness and related derivative contracts, net	(185,105)	0
Principal payments on finance lease obligations	(18,330)	(5,700)
Other	(393)	2,915
Net cash used in financing activities	(597,445)	(752,803)
Net decrease in cash and cash equivalents	(58,471)	(456,981)
Effect of exchange rate changes on cash and cash equivalents	620	(424)
Net decrease in cash and cash equivalents	(57,851)	(457,405)
Cash, cash equivalents and restricted cash at beginning of year	278,686	702,160
Cash, cash equivalents and restricted cash at end of period	220,835	244,755
CSC Holdings
Cash flows from operating activities:
Net income	278,539	10,122
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization (including impairments)	434,857	547,569
Loss (gain) on investments and sale of affiliate interests, net	(73,453)	455,819
Loss (gain) on derivative contracts, net	53,565	(439,861)
Amortization of deferred financing costs and discounts (premiums) on indebtedness	23,039	23,944
Share-based compensation expense	28,281	27,946
Deferred income taxes	29,165	172,835
Decrease in right-of-use assets	10,816	11,474
Provision for doubtful accounts	11,133	19,880
Other	1,074	1,849
Change in assets and liabilities, net of effects of acquisitions and dispositions:
Accounts receivable, trade	55,293	(4,458)
Prepaid expenses and other assets	(26,321)	(34,800)
Amounts due from and due to affiliates	3,882	(147,183)
Accounts payable and accrued liabilities	(29,611)	(165,723)
Deferred revenue	38,501	(5,153)
Liabilities related to interest rate swap contracts	(89,798)	122,849
Net cash provided by operating activities	748,962	597,109
Cash flows from investing activities:
Capital expenditures	(212,791)	(299,082)
Other, net	2,143	(2,669)
Net cash used in investing activities	(210,648)	(301,751)
Cash flows from financing activities:
Proceeds from long-term debt	150,000	0
Repayment of long-term debt	(225,863)	(18,183)
Proceeds from collateralized indebtedness and related derivative contracts, net	185,105	0
Repayment of collateralized indebtedness and related derivative contracts, net	(185,105)	0
Distributions to parent	501,000	720,350
Principal payments on finance lease obligations	(18,330)	(5,700)
Other	1,465	4,947
Net cash used in financing activities	(596,658)	(749,180)
Net decrease in cash and cash equivalents	(58,344)	(453,822)
Effect of exchange rate changes on cash and cash equivalents	620	(424)
Net decrease in cash and cash equivalents	(57,724)	(454,246)
Cash, cash equivalents and restricted cash at beginning of year	278,202	698,003
Cash, cash equivalents and restricted cash at end of period	$ 220,478	$ 243,757

DESCRIPTION OF BUSINESS AND REL

DESCRIPTION OF BUSINESS AND RELATED MATTERS	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND RELATED MATTERS	DESCRIPTION OF BUSINESS AND RELATED MATTERS The Company and Related Matters Altice USA, Inc. ("Altice USA") was incorporated in Delaware on September 14, 2015. Altice USA is majority-owned by Patrick Drahi through Next Alt. S.a.r.l. ("Next Alt"). Altice USA, through CSC Holdings, LLC (a wholly-owned subsidiary of Cablevision Systems Corporation) and its consolidated subsidiaries ("CSC Holdings," and collectively with Altice USA, the "Company"), principally provides broadband communications and video services in the United States. It markets its residential services primarily under two brands: Optimum, in the New York metropolitan area, and Suddenlink, principally in markets in the south-central United States. It operates enterprise services under the brands Lightpath and Altice Business. It delivers broadband, video, telephony services, proprietary content and advertising services to residential and business customers. In September 2019, the Company launched Altice Mobile, a full service voice and data offering, to consumers across its footprint. As these brands are managed on a consolidated basis, the Company classifies its operations in one segment. The accompanying consolidated financial statements ("consolidated financial statements") of Altice USA include the accounts of Altice USA and its majority-owned subsidiaries and the accompanying consolidated financial statements of CSC Holdings include the accounts of CSC Holdings and its majority-owned subsidiaries. Altice USA is a holding company and has no business operations independent of its CSC Holdings subsidiary, whose operating results and financial position are consolidated into Altice USA. The consolidated balance sheets and statements of operations of Altice USA are essentially identical to the consolidated balance sheets and statements of operations of CSC Holdings, with the following exceptions: Altice USA has additional cash and deferred taxes on its consolidated balance sheet. In addition, CSC Holdings and its subsidiaries have certain intercompany receivables from and payables to Altice USA. Differences between Altice USA's results of operations and those of CSC Holdings for the three months ended March 31, 2020 primarily include gain on investments and sale of affiliate interests, net and income tax expense recorded by Altice USA. The combined notes to the consolidated financial statements relate to the Company, which, except as noted, are essentially identical for Altice USA and CSC Holdings. All significant intercompany transactions and balances between Altice USA or CSC Holdings and their respective consolidated subsidiaries are eliminated in both sets of consolidated financial statements. Intercompany transactions between Altice USA and CSC Holdings are not eliminated in the CSC Holdings consolidated financial statements, but are eliminated in the Altice USA consolidated financial statements. The financial statements of CSC Holdings are included herein as supplemental information as CSC Holdings is not an SEC registrant.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	BASIS OF PRESENTATION The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and with the instructions to Form 10-Q and Article 10 of Regulation S-X for interim financial information. Accordingly, these financial statements do not include all the information and notes required for complete annual financial statements. The interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2020. The financial statements presented in this report are unaudited; however, in the opinion of management, such financial statements include all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of the results for the periods presented. The results of operations for the interim periods are not necessarily indicative of the results that might be expected for future interim periods or for the full year ending December 31, 2021. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. See Note 12 for a discussion of fair value estimates.

COMMON STOCK

COMMON STOCK	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Common stock	COMMON STOCK Share Repurchase Plan In June 2018, the Board of Directors of Altice USA authorized a share repurchase program of $2,000,000, and on July 30, 2019, the Board of Directors authorized a new incremental three-year share repurchase program of $5,000,000 that took effect following the completion in August 2019 of the $2,000,000 repurchase program. In November 2020, the Board of Directors authorized an additional incremental $2,000,000 of share repurchases bringing the total amount of cumulative share repurchases authorized to $9,000,000. Under these repurchase programs, shares of Altice USA Class A common stock may be purchased from time to time in the open market and may include trading plans entered into with one or more brokerage firms in accordance with Rule 10b5-1 under the Securities Exchange Act of 1934. Size and timing of these purchases will be determined based on market conditions and other factors. For the three months ended March 31, 2021, Altice USA repurchased an aggregate of 15,179,697 shares for a total purchase price of approximately $522,673. From inception through March 31, 2021, Altice USA repurchased an aggregate of 277,093,742 shares for a total purchase price of approximately $7,526,443. These acquired shares were retired and the cost of these shares was recorded in stockholders' deficiency in the consolidated balance sheet of Altice USA. As of March 31, 2021, Altice USA had approximately $1,473,557 of availability remaining under the incremental share repurchase program and had 461,977,407 combined Class A and Class B shares outstanding. Common Stock of Altice USA The following table provides details of Altice USA's shares of common stock outstanding: Shares of Common Stock Outstanding Class A Class B Balance at December 31, 2020 290,573,672 185,895,903 Conversion of Class B common stock to Class A common stock 97,510 (97,510) Option exercises 104,365 — Repurchase and retirement of Class A common shares in connection with the Company's share repurchase plan (discussed above) (15,179,697) — Treasury shares reissued 583,164 — Balance at March 31, 2021 276,179,014 185,798,393

Revenue Recognition and Deferre

Revenue Recognition and Deferred Revenue	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer	REVENUE The following table presents the composition of revenue: Three Months Ended March 31, 2021 2020 Broadband $ 970,571 $ 885,529 Video 905,834 947,061 Telephony 106,981 125,030 Residential revenue 1,983,386 1,957,620 Business services and wholesale revenue 367,216 364,530 News and advertising 105,070 105,540 Mobile 19,235 18,356 Other 3,914 4,210 Total revenue $ 2,478,821 $ 2,450,256 The Company is assessed non-income related taxes by governmental authorities, including franchising authorities (generally under multi-year agreements), and collects such taxes from its customers. In instances where the tax is being assessed directly on the Company, amounts paid to the governmental authorities are recorded as programming and other direct costs and amounts received from the customers are recorded as revenue. For the three months ended March 31, 2021, and 2020, the amount of franchise fees and certain other taxes and fees included as a component of revenue aggregated $66,056, and $64,910, respectively. Customer Contract Costs Deferred enterprise commission costs are included in other noncurrent assets in the consolidated balance sheets and totaled $18,864 and $19,959 as of March 31, 2021 and December 31, 2020, respectively.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share	NET INCOME (LOSS) PER SHARE Basic net income (loss) per common share attributable to Altice USA stockholders is computed by dividing net income (loss) attributable to Altice USA stockholders by the weighted average number of common shares outstanding during the period. Diluted income per common share attributable to Altice USA stockholders reflects the dilutive effects of stock options and restricted stock. For such awards that are performance based, the diluted effect is reflected upon the achievement of the performance criteria. Diluted net loss per common share attributable to Altice USA stockholders excludes the effects of common stock equivalents as they are anti-dilutive. The following table presents a reconciliation of weighted average shares used in the calculations of the basic and diluted net income per share attributable to Altice USA stockholders for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 (in thousands) Basic weighted average shares outstanding 469,233 621,414 Effect of dilution: Stock options 6,170 — Restricted stock 45 — Diluted weighted average shares outstanding 475,448 621,414 Weighted average shares excluded from diluted weighted average shares outstanding: Anti-dilutive shares 495 22,525 Performance stock units and restricted stock whose performance metrics have not been achieved. 8,748 8,981 Net income (loss) per membership unit for CSC Holdings is not presented since CSC Holdings is a limited liability company and a wholly-owned subsidiary of Altice USA.

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Mar. 31, 2020
Supplemental Cash Flow Elements [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION The Company's non-cash investing and financing activities and other supplemental data were as follows: Three Months Ended March 31, 2021 2020 Non-Cash Investing and Financing Activities: Altice USA and CSC Holdings: Property and equipment accrued but unpaid $ 266,995 $ 219,889 Unsettled purchases of shares of Altice USA, Inc. Class A common stock, pursuant to a share repurchase program 18,942 23,993 Right-of-use assets acquired in exchange for finance lease obligations 38,348 27,674 CSC Holdings: Distributions to parent 745 150,602 Altice USA: Cash interest paid 310,878 474,268 Income taxes paid, net 9,727 1,195 CSC Holdings: Cash interest paid 310,878 474,268 Income taxes paid, net 9,727 1,195

RESTRUCTURING AND OTHER EXPENSE

RESTRUCTURING AND OTHER EXPENSE	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND OTHER EXPENSE	RESTRUCTURING AND OTHER EXPENSE The Company's restructuring and other expense is comprised of the following: Three Months Ended March 31, 2021 2020 Contractual payments for terminated employees $ 1,856 $ 3,121 Facility realignment costs 324 1,979 Impairment of right-of-use operating lease assets 405 1,705 Transaction costs related to certain transactions not related to the Company's operations 624 489 $ 3,209 $ 7,294

LEASES

LEASES	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
OPERATING LEASES	LEASES The Company's operating leases are comprised primarily of facility leases and finance leases are comprised primarily of vehicle and equipment leases. Balance sheet information related to our leases is presented below: Balance Sheet location March 31, 2021 December 31, 2020 Operating leases: Right-of-use lease assets Right-of-use operating lease assets $ 234,358 $ 241,342 Right-of-use lease liability, current Other current liabilities 38,373 38,296 Right-of-use lease liability, long-term Right-of-use operating lease liability 248,758 257,424 Finance leases: Right-of-use lease assets Property, plant and equipment 195,354 170,155 Right-of-use lease liability, current Current portion of long-term debt 76,123 63,454 Right-of-use lease liability, long-term Long-term debt 103,532 96,183 The following provides details of the Company's lease expense: Three Months Ended March 31, 2021 2020 Operating lease expense, net $ 14,307 $ 15,004 Amortization of assets 11,574 4,460 Interest on lease liabilities 2,101 1,027 Total finance lease expense 13,675 5,487 $ 27,982 $ 20,491 Other information related to leases is presented below: As of March 31, 2021 2020 Right-of-use assets acquired in exchange for operating lease obligations $ 2,865 $ 12,875 Cash Paid For Amounts Included In Measurement of Liabilities: Operating cash flows related to finance leases 2,101 1,027 Operating cash flows related to operating leases 15,457 16,659 Weighted Average Remaining Lease Term: Operating leases 8.8 years 9.3 years Finance leases 2.4 years 3.1 years Weighted Average Discount Rate: Operating leases 5.60 % 5.90 % Finance leases 5.16 % 5.50 % The minimum future annual payments under non-cancellable leases during the next five years and thereafter, at rates now in force, are as follows: Finance leases Operating leases 2021 (excluding the three months ended March 31, 2021) $ 62,394 $ 30,274 2022 78,946 52,862 2023 43,839 45,139 2024 5,231 41,448 2025 292 33,458 Thereafter — 167,700 Total future minimum lease payments, undiscounted 190,702 370,881 Less: Imputed interest (11,047) (83,750) Present value of future minimum lease payments $ 179,655 $ 287,131

INTANGIBLE ASSETS

INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS	INTANGIBLE ASSETS The following table summarizes information relating to the Company's acquired amortizable intangible assets: As of March 31, 2021 As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Estimated Useful Lives Customer relationships $ 6,052,598 $ (3,618,697) $ 2,433,901 $ 6,052,598 $ (3,478,742) $ 2,573,856 3 to 18 years Trade names 1,081,083 (917,820) 163,263 1,081,083 (894,189) 186,894 2 to 5 years Other amortizable intangibles 56,762 (37,909) 18,853 56,747 (36,381) 20,366 1 to 15 years $ 7,190,443 $ (4,574,426) $ 2,616,017 $ 7,190,428 $ (4,409,312) $ 2,781,116 Amortization expense for the three months ended March 31, 2021 and 2020 aggregated $165,114 and $201,099, respectively. The carrying amount of indefinite-lived cable television franchises as of March 31, 2021 and December 31, 2020 was $13,068,017. The carrying amount of goodwill as of March 31, 2021 and December 31, 2020 was $8,160,566.

DEBT

DEBT	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
DEBT	DEBT The following table provides details of the Company's outstanding debt: Interest Rate March 31, 2021 December 31, 2020 Date Issued Maturity Date Principal Amount Carrying Amount (a) Principal Amount Carrying Amount (a) CSC Holdings Senior Notes: November 15, 2011 November 15, 2021 6.750 % $ 1,000,000 $ 992,691 $ 1,000,000 $ 989,917 September 27, 2012 September 15, 2022 5.875 % 649,024 621,617 649,024 617,333 May 23, 2014 June 1, 2024 5.250 % 750,000 700,419 750,000 697,041 October 18, 2018 April 1, 2028 7.500 % 4,118 4,112 4,118 4,112 November 27, 2018 April 1, 2028 7.500 % 1,045,882 1,044,462 1,045,882 1,044,424 July 10 and October 7, 2019 January 15, 2030 5.750 % 2,250,000 2,285,317 2,250,000 2,286,097 June 16, 2020 December 1, 2030 4.625 % 2,325,000 2,369,628 2,325,000 2,370,502 8,024,024 8,018,246 8,024,024 8,009,426 CSC Holdings Senior Guaranteed Notes: September 23, 2016 April 15, 2027 5.500 % 1,310,000 1,306,088 1,310,000 1,305,955 January 29, 2018 February 1, 2028 5.375 % 1,000,000 993,677 1,000,000 993,490 November 27, 2018 May 15, 2026 5.500 % 1,498,806 1,488,086 1,498,806 1,487,644 January 24, 2019 February 1, 2029 6.500 % 1,750,000 1,747,309 1,750,000 1,747,245 June 16, 2020 December 1, 2030 4.125 % 1,100,000 1,095,377 1,100,000 1,095,283 August 17, 2020 February 15, 2031 3.375 % 1,000,000 996,760 1,000,000 996,692 7,658,806 7,627,297 7,658,806 7,626,309 CSC Holdings Restricted Group Credit Facility: Revolving Credit Facility (c) 2.358 % (b) 575,000 566,720 625,000 616,027 Term Loan B July 17, 2025 2.356 % 2,887,500 2,877,145 2,895,000 2,884,065 Incremental Term Loan B-3 January 15, 2026 2.356 % 1,249,500 1,245,315 1,252,688 1,248,293 Incremental Term Loan B-5 April 15, 2027 2.606 % 2,970,000 2,950,038 2,977,500 2,956,807 7,682,000 7,639,218 7,750,188 7,705,192 Lightpath Senior Notes: September 29, 2020 September 15, 2028 5.625 % 415,000 406,400 415,000 406,176 Lightpath Senior Secured Notes: September 29, 2020 September 15, 2027 3.875 % 450,000 440,791 450,000 440,487 Lightpath Term Loan November 30, 2027 3.750 % 598,500 581,879 600,000 582,808 Lightpath Revolving Credit Facility (d) — — — — 1,463,500 1,429,070 1,465,000 1,429,471 Collateralized indebtedness (see Note 11) 1,759,017 1,677,985 1,699,566 1,617,506 Finance lease obligations (see Note 8) 179,655 179,655 159,637 159,637 Notes payable and supply chain financing (e) 118,065 118,065 183,690 174,801 26,885,067 26,689,536 26,940,911 26,722,342 Less: current portion of credit facility debt (78,750) (78,750) (78,750) (78,750) Less: current portion of senior notes (1,000,000) (992,691) (1,000,000) (989,917) Less: current portion of finance lease obligations (76,123) (76,123) (63,454) (63,454) Less: current portion of notes payable and supply chain financing (110,491) (110,491) (113,592) (113,592) (1,265,364) (1,258,055) (1,255,796) (1,245,713) Long-term debt $ 25,619,703 $ 25,431,481 $ 25,685,115 $ 25,476,629 (a) The carrying amount is net of the unamortized deferred financing costs and/or discounts/premiums and with respect to certain notes, a fair value adjustment resulting from the acquisitions of Cequel Corporation and Cablevision Systems Corporation. (b) At March 31, 2021, $137,875 of the revolving credit facility was restricted for certain letters of credit issued on behalf of the Company and $1,762,125 of the facility was undrawn and available, subject to covenant limitations. (c) The revolving credit facility of an aggregate principal amount of $2,475,000 matures in January 2024 and is priced at LIBOR plus 2.25%. In March 2021, a lender under the revolving credit facility extended the maturity date and reduced the interest rate on its aggregate principal amount of $200,000 which had an original maturity date of November 2021 and was priced at LIBOR plus 3.25%. (d) There were no borrowings outstanding under the Lightpath Revolving Credit Facility which provides for commitments in an aggregate principal amount of $100,000. Borrowings bear interest at a rate per annum equal to the adjusted LIBOR rate or the alternate base rate, as applicable, plus the applicable margin, where the applicable margin is (i) with respect to any alternate base rate loan, 2.25% per annum and (ii) with respect to any eurodollar loan, 3.25% per annum. (e) Includes $99,941 related to supply chain financing agreements that are required to be repaid within one year from the date of the respective agreement. The decrease in the principal amount at March 31, 2021 includes a $59,451 reclassification to collateralized indebtedness in connection with the maturity of a monetization contract related to the synthetic monetization closeout transaction in November 2019. For financing purposes, the Company has two debt silos: CSC Holdings and Lightpath. The CSC Holdings silo is structured as a restricted group (the "Restricted Group") and an unrestricted group, which includes certain designated subsidiaries and investments (the "Unrestricted Group"). The Restricted Group is comprised of CSC Holdings and substantially all of its wholly-owned operating subsidiaries excluding Cablevision Lightpath LLC ("Lightpath"), a 50.01% owned subsidiary of the Company, which became an unrestricted subsidiary in September 2020. These Restricted Group subsidiaries are subject to the covenants and restrictions of the credit facility and indentures governing the notes issued by CSC Holdings. The Lightpath silo includes all of its operating subsidiaries which are subject to the covenants and restrictions of the credit facility and indentures governing the notes issued by Lightpath. Both CSC Holdings and Lightpath's credit facilities agreements contains certain customary representations and warranties, affirmative covenants and events of default (including, among others, an event of default upon a change of control). If an event of default occurs, the lenders under the credit facilities will be entitled to take various actions, including the acceleration of amounts due under the credit facilities and all actions permitted to be taken by a secured creditor. As of March 31, 2021, CSC Holdings and Cablevision Lightpath were in compliance with applicable financial covenants under their respective credit facilities and with applicable financial covenants under each respective indenture by which the senior guaranteed notes, senior secured notes and senior notes were issued. Summary of Debt Maturities The future maturities of debt payable by the Company under its various debt obligations outstanding as of March 31, 2021, including notes payable and collateralized indebtedness (see Note 11), but excluding finance lease obligations (see Note 8), are as follows: 2021 $ 1,166,479 2022 734,667 2023 1,841,383 2024 1,403,889 2025 2,823,750 Thereafter 18,735,244

DERIVATIVE CONTRACTS AND COLLAT

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS	DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS Prepaid Forward Contracts The Company has entered into various transactions to limit the exposure against equity price risk on its shares of Comcast Corporation ("Comcast") common stock. The Company has monetized all of its stock holdings in Comcast through the execution of prepaid forward contracts, collateralized by an equivalent amount of the respective underlying stock. At maturity, the contracts provide for the option to deliver cash or shares of Comcast stock with a value determined by reference to the applicable stock price at maturity. These contracts, at maturity, are expected to offset declines in the fair value of these securities below the hedge price per share while allowing the Company to retain upside appreciation from the hedge price per share to the relevant cap price. The Company received cash proceeds upon execution of the prepaid forward contracts discussed above which has been reflected as collateralized indebtedness in the accompanying consolidated balance sheets. In addition, the Company separately accounts for the equity derivative component of the prepaid forward contracts. These equity derivatives have not been designated as hedges for accounting purposes. Therefore, the net fair values of the equity derivatives have been reflected in the accompanying consolidated balance sheets as an asset or liability and the net increases or decreases in the fair value of the equity derivative component of the prepaid forward contracts are included in gain (loss) on derivative contracts in the accompanying consolidated statements of operations. All of the Company's monetization transactions are obligations of its wholly-owned subsidiaries that are not part of the Restricted Group; however, CSC Holdings has provided guarantees of the subsidiaries' ongoing contract payment expense obligations and potential payments that could be due as a result of an early termination event (as defined in the agreements). If any one of these contracts was terminated prior to its scheduled maturity date, the Company would be obligated to repay the fair value of the collateralized indebtedness less the sum of the fair values of the underlying stock and equity collar, calculated at the termination date. As of March 31, 2021, the Company did not have an early termination shortfall relating to any of these contracts. The Company monitors the financial institutions that are counterparties to its equity derivative contracts. All of the counterparties to such transactions carry investment grade credit ratings as of March 31, 2021. In January 2021, the Company settled a collateralized debt and an equity derivative contract aggregating $185,102 upon maturity related to 5,337,750 shares of Comcast common stock held by us, with proceeds of $185,102 received in the current period pursuant to the synthetic monetization closeout transaction in November 2019. In connection with this transaction the Company recorded (i) a decrease in notes payable of $59,451 and (ii) an increase in collateralized debt of $59,451. Interest Rate Swap Contracts To manage interest rate risk, we have from time to time entered into interest rate swap contracts to adjust the proportion of total debt that is subject to variable and fixed interest rates. Such contracts effectively fix the borrowing rates on floating rate debt to provide an economic hedge against the risk of rising rates and/or effectively convert fixed rate borrowings to variable rates to permit the Company to realize lower interest expense in a declining interest rate environment. We monitor the financial institutions that are counterparties to our interest rate swap contracts and we only enter into interest rate swap contracts with financial institutions that are rated investment grade. All such contracts are carried at their fair market values on our consolidated balance sheet, with changes in fair value reflected in the consolidated statement of operations. As of March 31, 2021, the Company did not hold and has not issued derivative instruments for trading or speculative purposes. The following represents the location of the assets and liabilities associated with the Company's derivative instruments within the consolidated balance sheets: Derivatives Not Designated as Hedging Instruments Balance Sheet Location Fair Value at March 31, 2021 December 31, 2020 Asset Derivatives: Interest rate swap contracts Derivative contracts, short-term $ 8,252 $ 5,132 Prepaid forward contracts Derivative contracts, short-term — 45,653 Interest rate swap contracts Derivative contracts, long-term — 4,774 8,252 55,559 Liability Derivatives: Prepaid forward contracts Other current liabilities — (45,653) Interest rate swap contracts Other current liabilities (12,861) — Prepaid forward contracts Liabilities under derivative contracts, long-term (301,418) (247,853) Interest rate swap contracts Liabilities under derivative contracts, long-term (170,984) (275,297) $ (485,263) $ (568,803) The following table presents certain consolidated statement of operations data related to our derivative contracts and the underlying common stock: Three Months Ended March 31, 2021 2020 Gain (loss) on derivative contracts related to change in the value of equity derivative contracts related to Comcast common stock $ (53,565) $ 439,861 Change in the fair value of Comcast common stock included in gain (loss) on investments 73,453 (454,896) Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below 75,653 (54,832) In March 2020, the Company terminated two swap agreements whereby the Company was paying a floating rate of interest and receiving a fixed rate of interest on an aggregate notional value of $1,500,000. These contracts were due to mature in May 2026. In connection with the early termination, the Company received cash of $74,835 which has been recorded in loss on interest swap contracts, net in our consolidated statement of operations and presented in operating activities in our consolidated statement of cash flows. In addition, in March 2020, the Company executed amendments to two interest swap contracts that reduced the fixed rate of interest that the Company was paying on an aggregate notional value of $1,000,000 and extended the maturity date of the contracts to January 15, 2025 from January 15, 2022. The following is a summary of interest rate swap contracts outstanding at March 31, 2021: Trade Date Maturity Date Notional Amount Company Pays Company Receives December 2018 January 2025 $ 500,000 Fixed rate of 1.53% Three-month LIBOR December 2018 January 2022 500,000 Fixed rate of 2.733% Three-month LIBOR December 2018 January 2025 500,000 Fixed rate of 1.625% Three-month LIBOR December 2018 December 2026 750,000 Fixed rate of 2.9155% Three-month LIBOR December 2018 December 2026 750,000 Fixed rate of 2.9025% Three-month LIBOR March 2020 January 2025 500,000 Fixed rate of 1.458% Three-month LIBOR March 2020 January 2022 500,000 Three-month LIBOR Fixed rate of 2.733% April 2020 April 2021 2,850,000 Six-month LIBOR minus 0.5185% One-month LIBOR

FAIR VALUE MEASUREMENT

FAIR VALUE MEASUREMENT	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENT	FAIR VALUE MEASUREMENT The fair value hierarchy is based on inputs to valuation techniques that are used to measure fair value that are either observable or unobservable. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity's pricing based upon their own market assumptions. The fair value hierarchy consists of the following three levels: • Level I - Quoted prices for identical instruments in active markets. • Level II - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level III - Instruments whose significant value drivers are unobservable. The following table presents the Company's financial assets and financial liabilities that are measured at fair value on a recurring basis and their classification under the fair value hierarchy: Fair Value March 31, 2021 December 31, 2020 Assets: Money market funds Level I $ 150,965 $ 50,236 Investment securities pledged as collateral Level I 2,324,308 2,250,854 Prepaid forward contracts Level II — 45,653 Interest rate swap contracts Level II 8,252 9,906 Liabilities: Prepaid forward contracts Level II (301,418) 293,506 Interest rate swap contracts Level II (183,845) 275,297 The Company's money market funds which are classified as cash equivalents and investment securities pledged as collateral are classified within Level I of the fair value hierarchy because they are valued using quoted market prices. The Company's derivative contracts and liabilities under derivative contracts on the Company's consolidated balance sheets are valued using market-based inputs to valuation models. These valuation models require a variety of inputs, including contractual terms, market prices, yield curves, and measures of volatility. When appropriate, valuations are adjusted for various factors such as liquidity, bid/offer spreads and credit risk considerations. Such adjustments are generally based on available market evidence. Since model inputs can generally be verified and do not involve significant management judgment, the Company has concluded that these instruments should be classified within Level II of the fair value hierarchy. Fair Value of Financial Instruments The following methods and assumptions were used to estimate fair value of each class of financial instruments for which it is practicable to estimate: Credit Facility Debt, Collateralized Indebtedness, Senior Notes, Senior Guaranteed Notes, Senior Secured Notes, Notes Payable, and Supply Chain Financing The fair values of each of the Company's debt instruments are based on quoted market prices for the same or similar issues or on the current rates offered to the Company for instruments of the same remaining maturities. The fair value of notes payable is based primarily on the present value of the remaining payments discounted at the borrowing cost. The carrying value of outstanding amounts related to supply chain financing agreements approximates the fair value due to their short-term maturity (less than one year). The carrying values, estimated fair values, and classification under the fair value hierarchy of the Company's financial instruments, excluding those that are carried at fair value in the accompanying consolidated balance sheets, are summarized below: March 31, 2021 December 31, 2020 Fair Value Carrying Estimated Carrying Estimated Credit facility debt Level II $ 8,221,097 $ 8,280,500 $ 8,288,000 $ 8,350,188 Collateralized indebtedness Level II 1,677,985 1,753,986 1,617,506 1,692,724 Senior guaranteed notes and senior secured notes Level II 8,068,088 8,363,231 8,066,796 8,567,858 Senior notes Level II 8,424,646 8,734,561 8,415,602 9,024,990 Notes payable and supply chain financing Level II 118,065 118,183 174,801 175,251 $ 26,509,881 $ 27,250,461 $ 26,562,705 $ 27,811,011 (a) Amounts are net of unamortized deferred financing costs and discounts/premiums.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES In general, the Company is required to use an estimated annual effective tax rate ("AETR") to measure the income tax expense or benefit recognized on a year to date basis in an interim period. In addition, certain items included in income tax expense as well as the tax impact of certain items included in pretax income must be treated as discrete items. The income tax expense or benefit associated with these discrete items is fully recognized in the interim period in which the items occur. Altice USA For the three months ended March 31, 2021, Altice USA recorded a tax expense of $112,007 on pre-tax income of $390,546, resulting in an effective tax rate that was higher than the U.S. statutory tax rate. The higher tax rate was due to the impact of certain non-deductible expenses and state tax expense. For the three months ended March 31, 2020, Altice USA recorded a tax expense of $17,035 on pre-tax income of $15,497, resulting in an effective tax rate that was higher than the U.S. statutory tax rate. The higher tax rate was due to the impact of certain non-deductible expenses and certain state tax expense adjustments, partially offset by a benefit resulting from the Coronavirus Aid, Relief and Economic Security (“CARES Act”) enacted in March 2020. CSC Holdings For the three months ended March 31, 2021, CSC Holdings recorded a tax expense of $112,007 on pre-tax income of $390,546, resulting in an effective tax rate that was higher than the U.S. statutory tax rate. The higher tax rate was due to the impact of certain non-deductible expenses and state tax expense. For the three months ended March 31, 2020, CSC Holdings recorded a tax expense of $5,029 on pre-tax income of $15,151, resulting in an effective tax rate that was higher than the U.S. statutory tax rate. The higher tax rate was due to the impact of certain non-deductible expenses and certain state tax expense adjustments, partially offset by a benefit resulting from the CARES Act.

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION The following table presents share-based compensation expense recognized by the Company and unrecognized compensation costs: Share-Based Compensation Unrecognized Compensation Costs Three Months Ended March 31, 2021 2020 As of March 31, 2021 Carry Unit Plan $ 759 $ 3,120 $ 44 Awards issued pursuant to LTIP: Stock Option Awards 24,223 20,349 123,543 Performance Stock Units 2,982 3,901 60,675 Restricted Awards 317 576 549 $ 28,281 $ 27,946 $ 184,811 Carry Unit Plan The following table summarizes activity relating to the Company's Carry Unit Plan: Number of Time Weighted Average Grant Date Fair Value Balance, December 31, 2020 6,875,000 $ 3.41 Vested (5,375,000) 3.80 Balance, March 31, 2021 1,500,000 $ 1.99 The weighted average fair value per unit was $2.10 and $3.89, as of March 31, 2021 and December 31, 2020, respectively. Stock Option Awards The following table summarizes activity related to stock options granted to Company employees: Shares Under Option Weighted Average Weighted Average Remaining Aggregate Intrinsic Balance at December 31, 2020 37,062,146 $ 25.52 8.69 $ 457,608 Granted 409,478 34.78 Exercised (104,365) 17.79 Forfeited (360,778) 26.10 Balance at March 31, 2021 37,006,481 25.64 8.46 256,796 Options exercisable at March 31, 2021 3,141,750 $ 17.55 6.78 $ 47,070 (a) The aggregate intrinsic value is calculated as the difference between the exercise price and the closing price of Altice USA's Class A common stock at the respective date. The total unrecognized compensation cost related to stock options is expected to be recognized over a weighted-average period of approximately 2.56 years. The following weighted-average assumptions were used to calculate the fair values of stock option awards granted during the three months ended March 31, 2021: Risk-free interest rate 0.93% Expected life (in years) 6.18 Dividend yield —% Volatility 32.92% Grant date fair value $10.77 Performance Stock Unit Awards As of March 31, 2021, the Company had 7,330,235 PSUs outstanding. The PSUs have a weighted average grant date fair value of $10.65 per unit. The total unrecognized compensation cost related to outstanding PSUs is expected to be recognized over a weighted-average period of approximately 4.85 years.

AFFILIATE AND RELATED PARTY TRA

AFFILIATE AND RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
AFFILIATE AND RELATED PARTY TRANSACTIONS	AFFILIATE AND RELATED PARTY TRANSACTIONS Affiliate and Related Party Transactions Altice USA is controlled by Patrick Drahi who also controls Altice Europe N.V. ("Altice Europe") and its subsidiaries and other entities. As the transactions discussed below were conducted between entities under common control by Mr. Drahi, amounts charged for certain services may not have represented amounts that might have been received or incurred if the transactions were based upon arm's length negotiations. The following table summarizes the revenue and expenses related to services provided to or received from affiliates and related parties: Three Months Ended March 31, 2021 2020 Revenue $ 3,406 $ 3,488 Operating expenses: Programming and other direct costs $ (2,228) $ (2,189) Other operating expenses, net (3,179) (3,941) Operating expenses, net (5,407) (6,130) Net charges $ (2,001) $ (2,642) Capital Expenditures $ 10,621 $ 7,225 Revenue The Company recognized revenue primarily from the sale of advertising to a subsidiary of Altice Europe and a foundation controlled by Patrick Drahi. Programming and other direct costs Programming and other direct costs include costs incurred by the Company for advertising services provided by a subsidiary of Altice Europe. Other operating expenses, net Other operating expenses primarily include charges for services provided by certain subsidiaries of Altice Europe and other related parties. Capital Expenditures Capital expenditures primarily include costs for equipment purchased and software development services provided by subsidiaries of Altice Europe. Aggregate amounts that were due from and due to affiliates and related parties are summarized below: March 31, December 31, 2021 2020 Due from other affiliates and related parties $ 3,795 $ 4,262 Due to: Altice Europe $ 11,472 $ 7,938 Other affiliates and related parties 1,226 600 $ 12,698 $ 8,538 Amounts due from affiliates presented in the table above represent amounts paid by the Company on behalf of or for services provided to the respective related party. Amounts due to affiliates relate to the purchase of equipment and advertising services, as well as reimbursement for payments made on our behalf. CSC Holdings CSC Holdings made cash equity distribution payments to its parent aggregating $501,000, and $720,350 during the three months ended March 31, 2021 and 2020, respectively. CSC Holdings also recorded net non-cash equity contributions of $745 and $150,602 during the three months ended March 31, 2021 and 2020, respectively, which represent the non-cash settlement of intercompany balances with Altice USA. These balances primarily include amounts due to/due from Altice USA pursuant to a tax sharing agreement between the entities.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Matters In the latter half of 2018, eight named plaintiffs, each on behalf of a putative class of stockholders who purchased Company common stock in Altice USA's IPO pursuant to the Registration Statement and Prospectus, filed complaints (seven in New York State Supreme Court, one in United States District Court for the Eastern District of New York). The lawsuits name as defendants Altice USA, Altice Europe, and Altice USA's directors, among others, and assert that all defendants violated Sections 11 and 12 of the Securities Act of 1933 (the "Securities Act") and that the individual defendants violated Section 15 of the Securities Act as control persons. In a consolidated amended complaint filed in the lawsuit in the Eastern District of New York, plaintiff also asserts violations of Section 10(b) of the Securities Act of 1934 ("34 Act"), Rule 10b-5 promulgated thereunder, and Section 20 of the 34 Act against Altice USA, Altice Europe, and certain individual directors. The facts underlying each case are substantively similar, with plaintiffs alleging that the Registration Statement and Prospectus misrepresented or omitted material facts relating to the negative performance of Altice France and Altice Portugal, the disclosure of which in November 2017 negatively impacted the value of Altice USA’s stock. In June of 2019, plaintiffs in the New York State action filed a consolidated amended complaint, which the Company moved to dismiss in July of 2019. The Company moved to dismiss the complaint in the Eastern District of New York in October 2019. On June 26, 2020, the state Court granted the Company’s motion to dismiss. Plaintiffs in the New York State action filed a notice of appeal on July 21, 2020 and moved for leave to file an amended complaint on September 4, 2020. On September 23, 2020, the federal district court granted the Company’s motion to dismiss with leave for plaintiff to refile. On October 7, 2020, plaintiffs filed a second amended complaint in the Eastern District of New York. Following negotiations with the state and federal court plaintiffs, the parties executed a Memorandum of Understanding on February 12, 2021 to settle the litigation. That settlement remains subject to final documentation and court approval. On June 23, 2020, a purported stockholder of the Company filed a complaint in the Court of Chancery of the State of Delaware, derivatively on behalf of the Company, against Patrick Drahi, Next Alt S.A.R.L., and those directors of the Company who are members of the Compensation Committee (collectively, the “Director Defendants”). The Company is also named as a nominal defendant in the complaint. The complaint alleges that the Director Defendants breached their fiduciary duties to the Company’s stockholders, and wasted corporate assets, by approving certain equity grants for Patrick Drahi. The complaint seeks rescission of the equity awards, monetary damages, and costs and disbursements for the plaintiff. On October 15, 2020, the Director Defendants answered the complaint and the Company filed a general denial of liability. The Company intends to vigorously defend these lawsuits. Although the outcome of the matter cannot be predicted and the impact of the final resolution of these matters on the Company’s results of operations in any particular subsequent reporting period is not known at this time, management does not believe that the ultimate resolution of these matters will have a material adverse effect on the operations or financial position of the Company or the ability of the Company to meet its financial obligations as they become due. On November 6, 2018, Sprint Communications Company L.P ("Sprint") filed a complaint in the U.S. District Court for the District of Delaware alleging that the Company infringes Sprint’s patents purportedly by providing Voice over Internet Protocol ("VoIP") services. On December 3, 2018, Sprint filed a second complaint alleging that the Company infringes Sprint’s patents purportedly by providing certain VOD related services. The lawsuits are part of a pattern of litigation that was initiated as far back as 2005 by Sprint against numerous broadband and telecommunications providers, which has resulted in judgments and settlements of significant value for Sprint. The Company intends to vigorously defend the lawsuits. Although the outcome of the matter cannot be predicted and the impact of the final resolution of this matter on the Company’s results of operations in any particular subsequent reporting period is not known at this time, management does not believe that the ultimate resolution of the matter will have a material adverse effect on the operations or financial position of the Company or the ability of the Company to meet its financial obligations as they become due, but it could be material to the Company’s consolidated results of operations or cash flows for any one period. The Company receives notices from third parties and, in some cases, is named as a defendant in certain lawsuits claiming infringement of various patents relating to various aspects of the Company's businesses. In certain of these cases other industry participants are also defendants. In certain of these cases the Company expects that any potential liability would be the responsibility of the Company's equipment vendors pursuant to applicable contractual indemnification provisions. In the event that the Company is found to infringe on any patent rights, the Company may be subject to substantial damages and/or an injunction that could require the Company or its vendors to modify certain products and services the Company offers to its subscribers, as well as enter into royalty or license agreements with respect to the patents at issue. The Company believes that the claims are without merit, but is unable to predict the outcome of these matters or reasonably estimate a range of possible loss. In addition to the matters discussed above, the Company is party to various lawsuits, disputes and investigations, some of which may involve claims for substantial damages, fines or penalties. Although the outcome of these other matters cannot be predicted and the impact of the final resolution of these other matters on the Company's results of operations in a particular subsequent reporting period is not known, management does not believe that the resolution of these other lawsuits will have a material adverse effect on the financial position of the Company or the ability of the Company to meet its financial obligations as they become due.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS In April 2021, the Company completed its acquisition of the cable assets of Morris Broadband, LLC in North Carolina for $310,000, subject to certain closing adjustments as set forth in the asset purchase agreement.

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain reclassifications have been made to the 2020 financial statements to conform to the 2021 presentation.

Revenue Recognition and Defer_2

Revenue Recognition and Deferred Revenue (Policies)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Customer Contract Costs Deferred enterprise commission costs are included in other noncurrent assets in the consolidated balance sheets and totaled $18,864 and $19,959 as of March 31, 2021 and December 31, 2020, respectively.

COMMON STOCK (Tables)

COMMON STOCK (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of Stock by Class	Shares of Common Stock Outstanding Class A Class B Balance at December 31, 2020 290,573,672 185,895,903 Conversion of Class B common stock to Class A common stock 97,510 (97,510) Option exercises 104,365 — Repurchase and retirement of Class A common shares in connection with the Company's share repurchase plan (discussed above) (15,179,697) — Treasury shares reissued 583,164 — Balance at March 31, 2021 276,179,014 185,798,393

Revenue Recognition and Defer_3

Revenue Recognition and Deferred Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the composition of revenue: Three Months Ended March 31, 2021 2020 Broadband $ 970,571 $ 885,529 Video 905,834 947,061 Telephony 106,981 125,030 Residential revenue 1,983,386 1,957,620 Business services and wholesale revenue 367,216 364,530 News and advertising 105,070 105,540 Mobile 19,235 18,356 Other 3,914 4,210 Total revenue $ 2,478,821 $ 2,450,256

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares [Table Text Block]	The following table presents a reconciliation of weighted average shares used in the calculations of the basic and diluted net income per share attributable to Altice USA stockholders for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 (in thousands) Basic weighted average shares outstanding 469,233 621,414 Effect of dilution: Stock options 6,170 — Restricted stock 45 — Diluted weighted average shares outstanding 475,448 621,414 Weighted average shares excluded from diluted weighted average shares outstanding: Anti-dilutive shares 495 22,525 Performance stock units and restricted stock whose performance metrics have not been achieved. 8,748 8,981

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2021
Supplemental Cash Flow Elements [Abstract]
Non-Cash Investing and Financing Activities and Other Supplemental Data	The Company's non-cash investing and financing activities and other supplemental data were as follows: Three Months Ended March 31, 2021 2020 Non-Cash Investing and Financing Activities: Altice USA and CSC Holdings: Property and equipment accrued but unpaid $ 266,995 $ 219,889 Unsettled purchases of shares of Altice USA, Inc. Class A common stock, pursuant to a share repurchase program 18,942 23,993 Right-of-use assets acquired in exchange for finance lease obligations 38,348 27,674 CSC Holdings: Distributions to parent 745 150,602 Altice USA: Cash interest paid 310,878 474,268 Income taxes paid, net 9,727 1,195 CSC Holdings: Cash interest paid 310,878 474,268 Income taxes paid, net 9,727 1,195

RESTRUCTURING AND OTHER EXPEN_2

RESTRUCTURING AND OTHER EXPENSE (Tables)	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
Restructuring Cost Activity	The Company's restructuring and other expense is comprised of the following: Three Months Ended March 31, 2021 2020 Contractual payments for terminated employees $ 1,856 $ 3,121 Facility realignment costs 324 1,979 Impairment of right-of-use operating lease assets 405 1,705 Transaction costs related to certain transactions not related to the Company's operations 624 489 $ 3,209 $ 7,294

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Lesee, Operating Lease And Finance Lease, Liability	Balance sheet information related to our leases is presented below: Balance Sheet location March 31, 2021 December 31, 2020 Operating leases: Right-of-use lease assets Right-of-use operating lease assets $ 234,358 $ 241,342 Right-of-use lease liability, current Other current liabilities 38,373 38,296 Right-of-use lease liability, long-term Right-of-use operating lease liability 248,758 257,424 Finance leases: Right-of-use lease assets Property, plant and equipment 195,354 170,155 Right-of-use lease liability, current Current portion of long-term debt 76,123 63,454 Right-of-use lease liability, long-term Long-term debt 103,532 96,183
Lease, Cost	The following provides details of the Company's lease expense: Three Months Ended March 31, 2021 2020 Operating lease expense, net $ 14,307 $ 15,004 Amortization of assets 11,574 4,460 Interest on lease liabilities 2,101 1,027 Total finance lease expense 13,675 5,487 $ 27,982 $ 20,491
Lessee, Topic 842, Other Lease Information	Other information related to leases is presented below: As of March 31, 2021 2020 Right-of-use assets acquired in exchange for operating lease obligations $ 2,865 $ 12,875 Cash Paid For Amounts Included In Measurement of Liabilities: Operating cash flows related to finance leases 2,101 1,027 Operating cash flows related to operating leases 15,457 16,659 Weighted Average Remaining Lease Term: Operating leases 8.8 years 9.3 years Finance leases 2.4 years 3.1 years Weighted Average Discount Rate: Operating leases 5.60 % 5.90 % Finance leases 5.16 % 5.50 %
Finance Lease, Liability, Maturity	The minimum future annual payments under non-cancellable leases during the next five years and thereafter, at rates now in force, are as follows: Finance leases Operating leases 2021 (excluding the three months ended March 31, 2021) $ 62,394 $ 30,274 2022 78,946 52,862 2023 43,839 45,139 2024 5,231 41,448 2025 292 33,458 Thereafter — 167,700 Total future minimum lease payments, undiscounted 190,702 370,881 Less: Imputed interest (11,047) (83,750) Present value of future minimum lease payments $ 179,655 $ 287,131
Lessee, Operating Lease, Liability, Maturity	The minimum future annual payments under non-cancellable leases during the next five years and thereafter, at rates now in force, are as follows: Finance leases Operating leases 2021 (excluding the three months ended March 31, 2021) $ 62,394 $ 30,274 2022 78,946 52,862 2023 43,839 45,139 2024 5,231 41,448 2025 292 33,458 Thereafter — 167,700 Total future minimum lease payments, undiscounted 190,702 370,881 Less: Imputed interest (11,047) (83,750) Present value of future minimum lease payments $ 179,655 $ 287,131

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Acquired Finite-Lived Intangible Assets by Major Class	The following table summarizes information relating to the Company's acquired amortizable intangible assets: As of March 31, 2021 As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Estimated Useful Lives Customer relationships $ 6,052,598 $ (3,618,697) $ 2,433,901 $ 6,052,598 $ (3,478,742) $ 2,573,856 3 to 18 years Trade names 1,081,083 (917,820) 163,263 1,081,083 (894,189) 186,894 2 to 5 years Other amortizable intangibles 56,762 (37,909) 18,853 56,747 (36,381) 20,366 1 to 15 years $ 7,190,443 $ (4,574,426) $ 2,616,017 $ 7,190,428 $ (4,409,312) $ 2,781,116

DEBT (Tables)

DEBT (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities	The following table provides details of the Company's outstanding debt: Interest Rate March 31, 2021 December 31, 2020 Date Issued Maturity Date Principal Amount Carrying Amount (a) Principal Amount Carrying Amount (a) CSC Holdings Senior Notes: November 15, 2011 November 15, 2021 6.750 % $ 1,000,000 $ 992,691 $ 1,000,000 $ 989,917 September 27, 2012 September 15, 2022 5.875 % 649,024 621,617 649,024 617,333 May 23, 2014 June 1, 2024 5.250 % 750,000 700,419 750,000 697,041 October 18, 2018 April 1, 2028 7.500 % 4,118 4,112 4,118 4,112 November 27, 2018 April 1, 2028 7.500 % 1,045,882 1,044,462 1,045,882 1,044,424 July 10 and October 7, 2019 January 15, 2030 5.750 % 2,250,000 2,285,317 2,250,000 2,286,097 June 16, 2020 December 1, 2030 4.625 % 2,325,000 2,369,628 2,325,000 2,370,502 8,024,024 8,018,246 8,024,024 8,009,426 CSC Holdings Senior Guaranteed Notes: September 23, 2016 April 15, 2027 5.500 % 1,310,000 1,306,088 1,310,000 1,305,955 January 29, 2018 February 1, 2028 5.375 % 1,000,000 993,677 1,000,000 993,490 November 27, 2018 May 15, 2026 5.500 % 1,498,806 1,488,086 1,498,806 1,487,644 January 24, 2019 February 1, 2029 6.500 % 1,750,000 1,747,309 1,750,000 1,747,245 June 16, 2020 December 1, 2030 4.125 % 1,100,000 1,095,377 1,100,000 1,095,283 August 17, 2020 February 15, 2031 3.375 % 1,000,000 996,760 1,000,000 996,692 7,658,806 7,627,297 7,658,806 7,626,309 CSC Holdings Restricted Group Credit Facility: Revolving Credit Facility (c) 2.358 % (b) 575,000 566,720 625,000 616,027 Term Loan B July 17, 2025 2.356 % 2,887,500 2,877,145 2,895,000 2,884,065 Incremental Term Loan B-3 January 15, 2026 2.356 % 1,249,500 1,245,315 1,252,688 1,248,293 Incremental Term Loan B-5 April 15, 2027 2.606 % 2,970,000 2,950,038 2,977,500 2,956,807 7,682,000 7,639,218 7,750,188 7,705,192 Lightpath Senior Notes: September 29, 2020 September 15, 2028 5.625 % 415,000 406,400 415,000 406,176 Lightpath Senior Secured Notes: September 29, 2020 September 15, 2027 3.875 % 450,000 440,791 450,000 440,487 Lightpath Term Loan November 30, 2027 3.750 % 598,500 581,879 600,000 582,808 Lightpath Revolving Credit Facility (d) — — — — 1,463,500 1,429,070 1,465,000 1,429,471 Collateralized indebtedness (see Note 11) 1,759,017 1,677,985 1,699,566 1,617,506 Finance lease obligations (see Note 8) 179,655 179,655 159,637 159,637 Notes payable and supply chain financing (e) 118,065 118,065 183,690 174,801 26,885,067 26,689,536 26,940,911 26,722,342 Less: current portion of credit facility debt (78,750) (78,750) (78,750) (78,750) Less: current portion of senior notes (1,000,000) (992,691) (1,000,000) (989,917) Less: current portion of finance lease obligations (76,123) (76,123) (63,454) (63,454) Less: current portion of notes payable and supply chain financing (110,491) (110,491) (113,592) (113,592) (1,265,364) (1,258,055) (1,255,796) (1,245,713) Long-term debt $ 25,619,703 $ 25,431,481 $ 25,685,115 $ 25,476,629 (a) The carrying amount is net of the unamortized deferred financing costs and/or discounts/premiums and with respect to certain notes, a fair value adjustment resulting from the acquisitions of Cequel Corporation and Cablevision Systems Corporation. (b) At March 31, 2021, $137,875 of the revolving credit facility was restricted for certain letters of credit issued on behalf of the Company and $1,762,125 of the facility was undrawn and available, subject to covenant limitations. (c) The revolving credit facility of an aggregate principal amount of $2,475,000 matures in January 2024 and is priced at LIBOR plus 2.25%. In March 2021, a lender under the revolving credit facility extended the maturity date and reduced the interest rate on its aggregate principal amount of $200,000 which had an original maturity date of November 2021 and was priced at LIBOR plus 3.25%. (d) There were no borrowings outstanding under the Lightpath Revolving Credit Facility which provides for commitments in an aggregate principal amount of $100,000. Borrowings bear interest at a rate per annum equal to the adjusted LIBOR rate or the alternate base rate, as applicable, plus the applicable margin, where the applicable margin is (i) with respect to any alternate base rate loan, 2.25% per annum and (ii) with respect to any eurodollar loan, 3.25% per annum.
Schedule of Maturities of Long-term Debt	The future maturities of debt payable by the Company under its various debt obligations outstanding as of March 31, 2021, including notes payable and collateralized indebtedness (see Note 11), but excluding finance lease obligations (see Note 8), are as follows: 2021 $ 1,166,479 2022 734,667 2023 1,841,383 2024 1,403,889 2025 2,823,750 Thereafter 18,735,244

DERIVATIVE CONTRACTS AND COLL_2

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivatives	The following represents the location of the assets and liabilities associated with the Company's derivative instruments within the consolidated balance sheets: Derivatives Not Designated as Hedging Instruments Balance Sheet Location Fair Value at March 31, 2021 December 31, 2020 Asset Derivatives: Interest rate swap contracts Derivative contracts, short-term $ 8,252 $ 5,132 Prepaid forward contracts Derivative contracts, short-term — 45,653 Interest rate swap contracts Derivative contracts, long-term — 4,774 8,252 55,559 Liability Derivatives: Prepaid forward contracts Other current liabilities — (45,653) Interest rate swap contracts Other current liabilities (12,861) — Prepaid forward contracts Liabilities under derivative contracts, long-term (301,418) (247,853) Interest rate swap contracts Liabilities under derivative contracts, long-term (170,984) (275,297) $ (485,263) $ (568,803)
Location of Assets and Liabilities Associated With Derivative Instruments Within the Condensed Consolidated Balance Sheets	The following table presents certain consolidated statement of operations data related to our derivative contracts and the underlying common stock: Three Months Ended March 31, 2021 2020 Gain (loss) on derivative contracts related to change in the value of equity derivative contracts related to Comcast common stock $ (53,565) $ 439,861 Change in the fair value of Comcast common stock included in gain (loss) on investments 73,453 (454,896) Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below 75,653 (54,832) In March 2020, the Company terminated two swap agreements whereby the Company was paying a floating rate of interest and receiving a fixed rate of interest on an aggregate notional value of $1,500,000. These contracts were due to mature in May 2026. In connection with the early termination, the Company received cash of $74,835 which has been recorded in loss on interest swap contracts, net in our consolidated statement of operations and presented in operating activities in our consolidated statement of cash flows.
Schedule of Collateralized Debt Settlement	The following is a summary of interest rate swap contracts outstanding at March 31, 2021: Trade Date Maturity Date Notional Amount Company Pays Company Receives December 2018 January 2025 $ 500,000 Fixed rate of 1.53% Three-month LIBOR December 2018 January 2022 500,000 Fixed rate of 2.733% Three-month LIBOR December 2018 January 2025 500,000 Fixed rate of 1.625% Three-month LIBOR December 2018 December 2026 750,000 Fixed rate of 2.9155% Three-month LIBOR December 2018 December 2026 750,000 Fixed rate of 2.9025% Three-month LIBOR March 2020 January 2025 500,000 Fixed rate of 1.458% Three-month LIBOR March 2020 January 2022 500,000 Three-month LIBOR Fixed rate of 2.733% April 2020 April 2021 2,850,000 Six-month LIBOR minus 0.5185% One-month LIBOR

FAIR VALUE MEASUREMENT (Tables)

FAIR VALUE MEASUREMENT (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents the Company's financial assets and financial liabilities that are measured at fair value on a recurring basis and their classification under the fair value hierarchy: Fair Value March 31, 2021 December 31, 2020 Assets: Money market funds Level I $ 150,965 $ 50,236 Investment securities pledged as collateral Level I 2,324,308 2,250,854 Prepaid forward contracts Level II — 45,653 Interest rate swap contracts Level II 8,252 9,906 Liabilities: Prepaid forward contracts Level II (301,418) 293,506 Interest rate swap contracts Level II (183,845) 275,297
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	March 31, 2021 December 31, 2020 Fair Value Carrying Estimated Carrying Estimated Credit facility debt Level II $ 8,221,097 $ 8,280,500 $ 8,288,000 $ 8,350,188 Collateralized indebtedness Level II 1,677,985 1,753,986 1,617,506 1,692,724 Senior guaranteed notes and senior secured notes Level II 8,068,088 8,363,231 8,066,796 8,567,858 Senior notes Level II 8,424,646 8,734,561 8,415,602 9,024,990 Notes payable and supply chain financing Level II 118,065 118,183 174,801 175,251 $ 26,509,881 $ 27,250,461 $ 26,562,705 $ 27,811,011 (a) Amounts are net of unamortized deferred financing costs and discounts/premiums.

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Activity for Shares	The following table summarizes activity relating to the Company's Carry Unit Plan: Number of Time Weighted Average Grant Date Fair Value Balance, December 31, 2020 6,875,000 $ 3.41 Vested (5,375,000) 3.80 Balance, March 31, 2021 1,500,000 $ 1.99
Share-based Compensation, Stock Options, Activity	The following table summarizes activity related to stock options granted to Company employees: Shares Under Option Weighted Average Weighted Average Remaining Aggregate Intrinsic Balance at December 31, 2020 37,062,146 $ 25.52 8.69 $ 457,608 Granted 409,478 34.78 Exercised (104,365) 17.79 Forfeited (360,778) 26.10 Balance at March 31, 2021 37,006,481 25.64 8.46 256,796 Options exercisable at March 31, 2021 3,141,750 $ 17.55 6.78 $ 47,070
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	Risk-free interest rate 0.93% Expected life (in years) 6.18 Dividend yield —% Volatility 32.92% Grant date fair value $10.77

AFFILIATE AND RELATED PARTY T_2

AFFILIATE AND RELATED PARTY TRANSACTIONS (Tables)	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Summary of related party transactions	The following table summarizes the revenue and expenses related to services provided to or received from affiliates and related parties: Three Months Ended March 31, 2021 2020 Revenue $ 3,406 $ 3,488 Operating expenses: Programming and other direct costs $ (2,228) $ (2,189) Other operating expenses, net (3,179) (3,941) Operating expenses, net (5,407) (6,130) Net charges $ (2,001) $ (2,642) Capital Expenditures $ 10,621 $ 7,225 Aggregate amounts that were due from and due to affiliates and related parties are summarized below: March 31, December 31, 2021 2020 Due from other affiliates and related parties $ 3,795 $ 4,262 Due to: Altice Europe $ 11,472 $ 7,938 Other affiliates and related parties 1,226 600 $ 12,698 $ 8,538

DESCRIPTION OF BUSINESS AND R_2

DESCRIPTION OF BUSINESS AND RELATED MATTERS (Details)	3 Months Ended
	Mar. 31, 2021segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of segments	1

COMMON STOCK (Details)

COMMON STOCK (Details) - USD ($) $ in Thousands	3 Months Ended		34 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2021	Nov. 19, 2020	Jul. 31, 2019	Jun. 08, 2018
Common Stock Outstanding Roll Forward [Roll Forward]
Repurchase and retirement of Class A common shares in connection with the Company's share repurchase plan (discussed above)	(15,179,697)		(277,093,742)
Ending balance common stock, shares outstanding (in shares)	461,977,407		461,977,407
Value of shares repurchased	$ 522,673	$ 749,998	$ 7,526,443
Availability remaining under its stock repurchase program				$ 1,473,557
Common stock, shares outstanding (in shares)	461,977,407		461,977,407	461,977,407
Share repurchase authorized					$ 2,000,000		$ 2,000,000
Total shares authorized for repurchase
Common Stock Outstanding Roll Forward [Roll Forward]
Share repurchase authorized				$ 9,000,000
2019 Share Repurchase Authorization [Member]
Common Stock Outstanding Roll Forward [Roll Forward]
Share repurchase authorized						$ 5,000,000
Common Class A
Common Stock Outstanding Roll Forward [Roll Forward]
Common Stock, Shares, Outstanding, Beginning Balance	290,573,672
Conversion of Class B common stock to Class A common stock	97,510
Option exercises	104,365
Repurchase and retirement of Class A common shares in connection with the Company's share repurchase plan (discussed above)	(15,179,697)
Treasury shares reissued	583,164
Ending balance common stock, shares outstanding (in shares)	276,179,014		276,179,014
Common stock, shares outstanding (in shares)	276,179,014		276,179,014	276,179,014
Number of shares of common stock converted (in shares)	97,510
Common Class B
Common Stock Outstanding Roll Forward [Roll Forward]
Common Stock, Shares, Outstanding, Beginning Balance	185,895,903
Conversion of Class B common stock to Class A common stock	(97,510)
Option exercises	0
Repurchase and retirement of Class A common shares in connection with the Company's share repurchase plan (discussed above)	0
Ending balance common stock, shares outstanding (in shares)	185,798,393		185,798,393
Common stock, shares outstanding (in shares)	185,798,393		185,798,393	185,798,393
Number of shares of common stock converted (in shares)	(97,510)

Revenue Recognition and Defer_4

Revenue Recognition and Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Contract Assets and Liabilities [Line Items]
Revenues	$ 2,478,821	$ 2,450,256
Contract assets	$ 18,864		$ 19,959
Customer Contracts | Minimum
Contract Assets and Liabilities [Line Items]
Finite-lived intangible asset, useful life	3 years
Customer Contracts | Maximum
Contract Assets and Liabilities [Line Items]
Finite-lived intangible asset, useful life	5 years
Broadband [Member]
Contract Assets and Liabilities [Line Items]
Revenues	$ 970,571	885,529
Pay TV [Member]
Contract Assets and Liabilities [Line Items]
Revenues	905,834	947,061
Telephony [Member]
Contract Assets and Liabilities [Line Items]
Revenues	106,981	125,030
Total Residential Revenue
Contract Assets and Liabilities [Line Items]
Revenues	1,983,386	1,957,620
Business Services and Wholesale [Member]
Contract Assets and Liabilities [Line Items]
Revenues	367,216	364,530
Advertising and News [Member]
Contract Assets and Liabilities [Line Items]
Revenues	105,070	105,540
Mobile [Member]
Contract Assets and Liabilities [Line Items]
Revenues	19,235	18,356
Products And Services, Other [Member]
Contract Assets and Liabilities [Line Items]
Revenues	3,914	4,210
Franchise [Member]
Contract Assets and Liabilities [Line Items]
Franchise fees and other taxes and fees	$ 66,056	$ 64,910

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Basic weighted average common shares (in thousands)	469,233	621,414
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	6,170	0
Diluted weighted average common shares (in thousands)	475,448	621,414
Anti-dilutive shares	495	22,525
Performance stock units and restricted stock whose performance metrics have not been achieved.	8,748	8,981
Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	45	0

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Non-Cash Investing and Financing Activities:
Property and equipment accrued but unpaid	$ 266,995	$ 219,889
Unsettled purchases of shares of Altice USA, Inc. Class A common stock, pursuant to a share repurchase program	18,942	23,993
Right-of-use assets acquired in exchange for finance lease obligations	38,348	27,674
Distributions to parent	745	150,602
Supplemental Data:
Cash interest paid	310,878	474,268
Income taxes paid, net	9,727	1,195
CSC Holdings
Supplemental Data:
Cash interest paid	310,878	474,268
Income taxes paid, net	$ 9,727	$ 1,195

RESTRUCTURING AND OTHER EXPEN_3

RESTRUCTURING AND OTHER EXPENSE (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Reserve [Roll Forward]
Restructuring Charges	$ 3,209	$ 7,294
Restructuring expense relating to right of use operating leases	405	1,705
Transaction costs	624	489
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	1,856	3,121
Accrual, ending balance	13,185
Facility Realignment and Other Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	324	$ 1,979
Accrual, ending balance	$ 5,503

LEASES - Narrative (Details)

LEASES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Leases [Abstract]
Right-of-use operating lease assets	$ 234,358		$ 241,342
Operating Lease, Liability, Current	38,373		38,296
Operating Lease, Liability, Noncurrent	248,758		257,424
Finance Lease, Right-of-Use Asset	195,354		170,155
Finance Lease, Liability, Current	76,123		63,454
Finance Lease, Liability, Noncurrent	103,532		$ 96,183
Operating Lease Expense, Net	14,307	$ 15,004
Finance Lease, Right-of-Use Asset, Amortization	11,574	4,460
Finance Lease, Interest Expense	2,101	1,027
Finance Lease, Cost	13,675	5,487
Finance And Operating Lease, Lessee Expense	27,982	20,491
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	2,865	12,875
Finance Lease, Interest Payment on Liability	2,101	1,027
Operating Lease, Payments	$ 15,457	$ 16,659
Operating Lease, Weighted Average Remaining Lease Term	8 years 9 months 18 days	9 years 3 months 18 days
Finance Lease, Weighted Average Remaining Lease Term	2 years 4 months 24 days	3 years 1 month 6 days
Operating Lease, Weighted Average Discount Rate, Percent	5.60%	5.90%
Finance Lease, Weighted Average Discount Rate, Percent	5.16%	5.50%

LEASES (Details)

LEASES (Details) $ in Thousands	Mar. 31, 2021USD ($)
Finance Lease, Liability, Payments, Due Next Twelve Months	$ 62,394
Finance Lease, Liability, Payments, Due Year Two	78,946
Finance Lease, Liability, Payments, Due Year Three	43,839
Finance Lease, Liability, Payments, Due Year Four	5,231
Finance Lease, Liability, Payments, Due Year Five	292
Finance Lease, Liability, Payments, Due after Year Five	0
Finance Lease, Liability, Payment, Due, Total	190,702
Finance Leases, Future Minimum Payments, Interest Included in Payments	11,047
Finance Leases, Future Minimum Payments, Present Value of Net Minimum Payments	179,655
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	30,274
Lessee, Operating Lease, Liability, Payments, Due Year Two	52,862
Lessee, Operating Lease, Liability, Payments, Due Year Three	45,139
Lessee, Operating Lease, Liability, Payments, Due Year Four	41,448
Lessee, Operating Lease, Liability, Payments, Due Year Five	33,458
Lessee, Operating Lease, Liability, Payments, Due after Year Five	167,700
Lessee, Operating Lease, Liability, Payments, Due, Total	370,881
Operating Leases, Future Minimum Payments, Interest Included in Payments	83,750
Operating Leases, Future Minimum Payments, Present Value of Net Minimum Payments	$ 287,131

INTANGIBLE ASSETS - Summary of

INTANGIBLE ASSETS - Summary of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 7,190,443	$ 7,190,428
Accumulated Amortization	(4,574,426)	(4,409,312)
Net Carrying Amount	2,616,017	2,781,116
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,052,598	6,052,598
Accumulated Amortization	(3,618,697)	(3,478,742)
Net Carrying Amount	2,433,901	2,573,856
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,081,083	1,081,083
Accumulated Amortization	(917,820)	(894,189)
Net Carrying Amount	163,263	186,894
Other amortizable intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	56,762	56,747
Accumulated Amortization	(37,909)	(36,381)
Net Carrying Amount	$ 18,853	$ 20,366
Minimum | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	3 years
Minimum | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	2 years
Minimum | Other amortizable intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	1 year
Maximum | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	18 years
Maximum | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	5 years
Maximum | Other amortizable intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	15 years

INTANGIBLE ASSETS - Narrative (

INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 165,114	$ 201,099

INTANGIBLE ASSETS - Indefinite-

INTANGIBLE ASSETS - Indefinite-lived assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 8,160,566	$ 8,160,566
Cable television franchises	$ 13,068,017	$ 13,068,017

DEBT - Credit Silo Combination

DEBT - Credit Silo Combination (Details) - USD ($)	1 Months Ended	3 Months Ended
	Sep. 30, 2020	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount		$ 26,885,067,000	$ 26,940,911,000
Long-term debt		26,689,536,000	26,722,342,000
Face Amount of Senior Notes and Senior Guaranteed Notes		7,658,806,000	7,658,806,000
Carrying amount of Senior Notes and Senior Guaranteed Notes		7,627,297,000	7,626,309,000
Face amount of Credit Facility Debt		7,682,000,000	7,750,188,000
Carrying value of Credit Facility Debt		7,639,218,000	7,705,192,000
Finance Lease, Liability		179,655,000	159,637,000
Debt		1,258,055,000	1,245,713,000
Finance Lease, Liability, Current		76,123,000	63,454,000
Long-term debt, net of current maturities		25,431,481,000	25,476,629,000
Principal Amount		26,885,067,000	26,940,911,000
Face Amount of Senior Notes		8,024,024,000	8,024,024,000
Carrying amount of Senior Notes		8,018,246,000	8,009,426,000
Senior Notes, Current		(992,691,000)	(989,917,000)
Cablevision Lightpath
Debt Instrument [Line Items]
Face Amount of Senior Notes and Senior Secured Notes		1,463,500,000	1,465,000,000
Carrying amount of Senior Notes and Senior Secured Notes		1,429,070,000	1,429,471,000
Loans Payable
Debt Instrument [Line Items]
Principal amount		110,491,000	113,592,000
Long-term debt		110,491,000	113,592,000
Principal Amount		110,491,000	113,592,000
Credit Facility [Domain]
Debt Instrument [Line Items]
Principal amount		78,750,000	78,750,000
Debt		78,750,000	78,750,000
Principal Amount		78,750,000	78,750,000
Short-term Debt
Debt Instrument [Line Items]
Principal amount		1,265,364,000	1,255,796,000
Debt		1,258,055,000	1,245,713,000
Principal Amount		1,265,364,000	1,255,796,000
Incremental Term Loan B-3 | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		$ 1,249,500,000	1,252,688,000
Stated interest rate		2.356%
Credit facility		$ 1,245,315,000	1,248,293,000
Principal Amount		1,249,500,000	1,252,688,000
CSC Holdings Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Principal amount		$ 575,000,000	625,000,000
Stated interest rate		2.358%
Line of Credit Facility, Maximum Borrowing Capacity		$ 2,475,000,000
Credit facility		566,720,000	616,027,000
Principal Amount		$ 575,000,000	625,000,000
CSC Holdings Revolving Credit Facility | Secured Debt [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
CSC Holdings Term Loan B | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		$ 2,887,500,000	2,895,000,000
Stated interest rate		2.356%
Credit facility		$ 2,877,145,000	2,884,065,000
Principal Amount		2,887,500,000	2,895,000,000
Incremental Term Loan B-5 | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		$ 2,970,000,000	2,977,500,000
Stated interest rate		2.606%
Credit facility		$ 2,950,038,000	2,956,807,000
Principal Amount		2,970,000,000	2,977,500,000
Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		1,759,017,000	1,699,566,000
Long-term debt		1,677,985,000	1,617,506,000
Principal Amount		1,759,017,000	1,699,566,000
Loans Payable
Debt Instrument [Line Items]
Principal amount		118,065,000	183,690,000
Long-term debt		118,065,000	174,801,000
Principal Amount		118,065,000	183,690,000
Cablevision Lightpath Term B Loan | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		$ 598,500,000	600,000,000
Stated interest rate		3.75%
Credit facility		$ 581,879,000	582,808,000
Principal Amount		598,500,000	600,000,000
Cablevision Lightpath Term B Loan | Secured Debt [Member] | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Cablevision Lightpath Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Principal amount		0	0
Line of Credit Facility, Maximum Borrowing Capacity		100,000,000
Credit facility		0	0
Principal Amount		0	0
Senior Notes | 8.0% Notes due April 15, 2020
Debt Instrument [Line Items]
Principal amount		$ 1,000,000,000	1,000,000,000
Stated interest rate		3.375%
Outstanding debt		$ 996,760,000	996,692,000
Principal Amount		1,000,000,000	1,000,000,000
Senior Notes | 6.75% Notes due November 15, 2021
Debt Instrument [Line Items]
Principal amount		$ 1,000,000,000	1,000,000,000
Stated interest rate		6.75%
Outstanding debt		$ 992,691,000	989,917,000
Principal Amount		1,000,000,000	1,000,000,000
Senior Notes | 5.875% Notes due September 15, 2022
Debt Instrument [Line Items]
Principal amount		$ 649,024,000	649,024,000
Stated interest rate		5.875%
Outstanding debt		$ 621,617,000	617,333,000
Principal Amount		649,024,000	649,024,000
Senior Notes | 5.25% Notes due June 1, 2024
Debt Instrument [Line Items]
Principal amount		$ 750,000,000	750,000,000
Stated interest rate		5.25%
Outstanding debt		$ 700,419,000	697,041,000
Principal Amount		750,000,000	750,000,000
Senior Notes | Cablevision 7.500% Notes due April 1, 2028
Debt Instrument [Line Items]
Principal amount		$ 4,118,000	4,118,000
Stated interest rate		7.50%
Outstanding debt		$ 4,112,000	4,112,000
Principal Amount		4,118,000	4,118,000
Senior Notes | CSC Holdings 7.500% Notes due April 1, 2028
Debt Instrument [Line Items]
Principal amount		$ 1,045,882,000	1,045,882,000
Stated interest rate		7.50%
Outstanding debt		$ 1,044,462,000	1,044,424,000
Principal Amount		1,045,882,000	1,045,882,000
Senior Notes | CSC Holdings 5.750% Notes due January 15, 2030
Debt Instrument [Line Items]
Principal amount		$ 2,250,000,000	2,250,000,000
Stated interest rate		5.75%
Outstanding debt		$ 2,285,317,000	2,286,097,000
Principal Amount		2,250,000,000	2,250,000,000
Senior Notes | CSC Holdings 4.625% Notes due December 1, 2030
Debt Instrument [Line Items]
Principal amount		$ 2,325,000,000	2,325,000,000
Stated interest rate		4.625%
Outstanding debt		$ 2,369,628,000	2,370,502,000
Principal Amount		2,325,000,000	2,325,000,000
Senior Notes | Cablevision Lightpath LLC 5.625% Notes due September 15, 2028
Debt Instrument [Line Items]
Principal amount		$ 415,000,000	415,000,000
Stated interest rate		5.625%
Outstanding debt		$ 406,400,000	406,176,000
Principal Amount		415,000,000	415,000,000
Secured Debt [Member] | CSC Holdings 5.500% Notes due May 15, 2026
Debt Instrument [Line Items]
Principal amount		$ 1,498,806,000	1,498,806,000
Stated interest rate		5.50%
Outstanding debt		$ 1,488,086,000	1,487,644,000
Principal Amount		1,498,806,000	1,498,806,000
Secured Debt [Member] | 5.5% Notes due April 15, 2027
Debt Instrument [Line Items]
Principal amount		$ 1,310,000,000	1,310,000,000
Stated interest rate		5.50%
Outstanding debt		$ 1,306,088,000	1,305,955,000
Principal Amount		1,310,000,000	1,310,000,000
Secured Debt [Member] | 5.375% Senior Guaranteed Notes Due February 1, 2028
Debt Instrument [Line Items]
Principal amount		$ 1,000,000,000	1,000,000,000
Stated interest rate		5.375%
Outstanding debt		$ 993,677,000	993,490,000
Principal Amount		1,000,000,000	1,000,000,000
Secured Debt [Member] | CSC Holdings 6.500% Notes due February 1, 2029
Debt Instrument [Line Items]
Principal amount		$ 1,750,000,000	1,750,000,000
Stated interest rate		6.50%
Outstanding debt		$ 1,747,309,000	1,747,245,000
Principal Amount		1,750,000,000	1,750,000,000
Secured Debt [Member] | CSC Holdings 4.125% Notes due December 1, 2030
Debt Instrument [Line Items]
Principal amount		$ 1,100,000,000	1,100,000,000
Stated interest rate		4.125%
Outstanding debt		$ 1,095,377,000	1,095,283,000
Principal Amount		1,100,000,000	1,100,000,000
Secured Debt [Member] | Cablevision Lightpath LLC 3.875% Notes due September 15, 2027
Debt Instrument [Line Items]
Principal amount		$ 450,000,000	450,000,000
Stated interest rate		3.875%
Outstanding debt		$ 440,791,000	440,487,000
Principal Amount		450,000,000	450,000,000
Long-term Debt
Debt Instrument [Line Items]
Principal amount		25,619,703,000	25,685,115,000
Long-term debt, net of current maturities		25,431,481,000	25,476,629,000
Principal Amount		$ 25,619,703,000	$ 25,685,115,000

DEBT - Schedule of Exchange Agr

DEBT - Schedule of Exchange Agreement (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount	$ 26,885,067	$ 26,940,911

DEBT - CSC Holdings Credit Faci

DEBT - CSC Holdings Credit Facilities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount	$ 26,885,067,000		$ 26,940,911,000
Proceeds from long-term debt	150,000,000	$ 0
Repayments of line of credit	225,863,000	18,183,000
CSC Holdings
Debt Instrument [Line Items]
Cash distributions to parent	501,000,000	720,350,000
Proceeds from long-term debt	150,000,000	0
Repayments of line of credit	225,863,000	$ 18,183,000
5.5% Notes due April 15, 2027 | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount	$ 1,310,000,000		1,310,000,000
Stated interest rate	5.50%
8.0% Notes due April 15, 2020 | Senior Notes
Debt Instrument [Line Items]
Principal amount	$ 1,000,000,000		1,000,000,000
Stated interest rate	3.375%
Secured Debt [Member] | CSC Holdings Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Secured Debt [Member] | Incremental Term Loan B-3
Debt Instrument [Line Items]
Principal amount	$ 1,249,500,000		1,252,688,000
Secured Debt [Member] | Incremental Term Loan B-5
Debt Instrument [Line Items]
Principal amount	$ 2,970,000,000		2,977,500,000
Secured Debt [Member] | CSC Holdings Revolving Credit Facility - Non-Extend Creditors [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Revolving Credit Facility | CSC Holdings Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,475,000,000
Principal amount	$ 575,000,000		$ 625,000,000

DEBT - Cequel Credit Facilities

DEBT - Cequel Credit Facilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Principal amount	$ 26,885,067	$ 26,940,911

DEBT - Credit Facilities Outsta

DEBT - Credit Facilities Outstanding (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 26,689,536,000	$ 26,722,342,000
CSC Holdings Revolving Credit Facility, Portion Due October 9, 2020 | Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200,000
CSC Holdings Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Stated interest rate	2.358%
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,475,000,000
Credit facility, Carrying Value	566,720,000	616,027,000
Letters of credit outstanding	137,875,000
Line of credit facility, remaining borrowing capacity	$ 1,762,125,000
CSC Holdings Term Loan B | Secured Debt [Member]
Debt Instrument [Line Items]
Stated interest rate	2.356%
Credit facility, Carrying Value	$ 2,877,145,000	2,884,065,000
Incremental Term Loan B-3 | Secured Debt [Member]
Debt Instrument [Line Items]
Stated interest rate	2.356%
Credit facility, Carrying Value	$ 1,245,315,000	1,248,293,000
Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,677,985,000	$ 1,617,506,000

DEBT - Senior Guaranteed Notes

DEBT - Senior Guaranteed Notes and Senior Notes and Debentures (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount	$ 26,885,067,000		$ 26,940,911,000
Less: Current portion	992,691,000		989,917,000
Face Amount of Senior Notes and Senior Guaranteed Notes	7,658,806,000		7,658,806,000
Carrying amount of Senior Notes and Senior Guaranteed Notes	7,627,297,000		7,626,309,000
Face amount of Credit Facility Debt	7,682,000,000		7,750,188,000
Carrying value of Credit Facility Debt	7,639,218,000		7,705,192,000
Finance Lease, Liability	179,655,000		159,637,000
Long-term debt	26,689,536,000		26,722,342,000
Debt	1,258,055,000		1,245,713,000
Finance Lease, Liability, Current	76,123,000		63,454,000
Long-term debt, net of current maturities	25,431,481,000		25,476,629,000
Repayments of line of credit	225,863,000	$ 18,183,000
Loans Payable
Debt Instrument [Line Items]
Principal amount	110,491,000		113,592,000
Long-term debt	110,491,000		113,592,000
Short-term Debt
Debt Instrument [Line Items]
Principal amount	1,265,364,000		1,255,796,000
Debt	1,258,055,000		1,245,713,000
Credit Facility [Domain]
Debt Instrument [Line Items]
Principal amount	78,750,000		78,750,000
Debt	78,750,000		78,750,000
Incremental Term Loan B-3 | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount	$ 1,249,500,000		1,252,688,000
Stated interest rate	2.356%
Credit facility	$ 1,245,315,000		1,248,293,000
Incremental Term Loan B-5 | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount	$ 2,970,000,000		2,977,500,000
Stated interest rate	2.606%
Credit facility	$ 2,950,038,000		2,956,807,000
Loans Payable
Debt Instrument [Line Items]
Principal amount	118,065,000		183,690,000
Long-term debt	118,065,000		174,801,000
Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount	1,759,017,000		1,699,566,000
Long-term debt	1,677,985,000		1,617,506,000
CSC Holdings Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Principal amount	$ 575,000,000		625,000,000
Stated interest rate	2.358%
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,475,000,000
Credit facility	$ 566,720,000		616,027,000
Secured Debt [Member] | 5.5% Notes due April 15, 2027
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Principal amount	$ 1,310,000,000		1,310,000,000
Carrying Amount	$ 1,306,088,000		1,305,955,000
Secured Debt [Member] | 5.375% Senior Guaranteed Notes Due February 1, 2028
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.375%
Principal amount	$ 1,000,000,000		1,000,000,000
Carrying Amount	$ 993,677,000		993,490,000
Secured Debt [Member] | CSC Holdings 5.500% Notes due May 15, 2026
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Principal amount	$ 1,498,806,000		1,498,806,000
Carrying Amount	$ 1,488,086,000		1,487,644,000
Secured Debt [Member] | CSC Holdings 6.500% Notes due February 1, 2029
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Principal amount	$ 1,750,000,000		1,750,000,000
Carrying Amount	1,747,309,000		1,747,245,000
Long-term Debt
Debt Instrument [Line Items]
Principal amount	25,619,703,000		25,685,115,000
Long-term debt, net of current maturities	$ 25,431,481,000		25,476,629,000
Senior Notes | 6.75% Notes due November 15, 2021
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.75%
Principal amount	$ 1,000,000,000		1,000,000,000
Carrying Amount	$ 992,691,000		989,917,000
Senior Notes | 5.25% Notes due June 1, 2024
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.25%
Principal amount	$ 750,000,000		750,000,000
Carrying Amount	$ 700,419,000		697,041,000
Senior Notes | CSC Holdings 7.500% Notes due April 1, 2028
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Principal amount	$ 1,045,882,000		1,045,882,000
Carrying Amount	$ 1,044,462,000		1,044,424,000
Senior Notes | 8.0% Notes due April 15, 2020
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.375%
Principal amount	$ 1,000,000,000		1,000,000,000
Carrying Amount	$ 996,760,000		996,692,000
Senior Notes | 5.875% Notes due September 15, 2022
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.875%
Principal amount	$ 649,024,000		649,024,000
Carrying Amount	$ 621,617,000		617,333,000
Senior Notes | Cablevision 7.500% Notes due April 1, 2028
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Principal amount	$ 4,118,000		4,118,000
Carrying Amount	$ 4,112,000		4,112,000
Senior Notes | CSC Holdings 5.750% Notes due January 15, 2030
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Principal amount	$ 2,250,000,000		2,250,000,000
Carrying Amount	$ 2,285,317,000		$ 2,286,097,000

DEBT - Senior Guaranteed Notes,

DEBT - Senior Guaranteed Notes, Senior Secured Notes, and Senior Notes and Debentures (Details) - USD ($)	1 Months Ended	3 Months Ended
	Sep. 30, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount		$ 26,885,067,000		$ 26,940,911,000
Long-term debt		26,689,536,000		26,722,342,000
Stock Issued During Period, Value, New Issues		2,044,000	$ 2,507,000
Collateralized Agreements		99,941,000
Notes Payable that will be reclassed to collateralized debt upon maturity		$ 59,451,000
Cablevision Lightpath LLC | Cablevision Lightpath LLC
Debt Instrument [Line Items]
Ownership percentage of noncontrolling interest		50.01%
CSC Holdings Revolving Credit Facility, Portion Due October 9, 2020 | Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 200,000
Cablevision Lightpath Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Principal amount		0		0
Line of Credit Facility, Maximum Borrowing Capacity		100,000,000
Cablevision Lightpath Term B Loan | Secured Debt [Member]
Debt Instrument [Line Items]
Principal amount		598,500,000		600,000,000
Cablevision Lightpath Term B Loan | Secured Debt [Member] | Alternate Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Cablevision Lightpath Term B Loan | Secured Debt [Member] | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Senior Notes | CSC Holdings 5.750% Notes due January 15, 2030
Debt Instrument [Line Items]
Principal amount		$ 2,250,000,000		2,250,000,000
Stated interest rate		5.75%
Secured Debt [Member] | 5.5% Notes due April 15, 2027
Debt Instrument [Line Items]
Principal amount		$ 1,310,000,000		1,310,000,000
Stated interest rate		5.50%
Long-term Debt
Debt Instrument [Line Items]
Principal amount		$ 25,619,703,000		$ 25,685,115,000

DEBT - Summary of Debt Maturiti

DEBT - Summary of Debt Maturities (Details) $ in Thousands	Mar. 31, 2021USD ($)
Debt Disclosure [Abstract]
2019	$ 1,166,479
2020	734,667
2021	1,841,383
2022	1,403,889
2023	2,823,750
Thereafter	$ 18,735,244

DERIVATIVE CONTRACTS AND COLL_3

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Settlements of Collateralized Indebtedness (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Derivative [Line Items]
Number of shares (in shares)	5,337,750
Notes Payable that will be reclassed to collateralized debt upon maturity		$ 59,451
Proceeds from Issuance of Secured Debt		185,105	$ 0
Comcast Synthetic Monetization Closeout
Derivative [Line Items]
Proceeds from Issuance of Secured Debt		$ 185,102

DERIVATIVE CONTRACTS AND COLL_4

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Location of Assets and Liabilities Within the Consolidated Balance Sheets (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 8,252	$ 55,559
Liability Derivatives	485,263	568,803
Interest Rate Swap | Current derivative contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	8,252	5,132
Interest Rate Swap | Long-term derivative contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	4,774
Interest Rate Swap | Short-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	12,861	0
Interest Rate Swap | Long-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	(170,984)	(275,297)
Prepaid forward contracts | Current derivative contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		0	$ 45,653
Prepaid forward contracts | Short-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	(45,653)
Prepaid forward contracts | Long-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ (301,418)	$ (247,853)

DERIVATIVE CONTRACTS AND COLL_5

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative [Line Items]
Gain (loss) on derivative contracts related to change in the value of equity derivative contracts related to Comcast common stock	$ (53,565)	$ 439,861
Change in the fair value of Comcast common stock included in gain (loss) on investments	73,453	(454,896)
Gain (loss) on interest rate swap contracts, net of a gain of $74,835 recorded in the 2020 period in connection with the early termination of the swap agreements discussed below	$ 75,653	(54,832)
Notes related to derivative contracts
Derivative [Line Items]
Gain (loss) on derivative contracts related to change in the value of equity derivative contracts related to Comcast common stock		$ 439,861

DERIVATIVE CONTRACTS AND COLL_6

DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Schedule of Interest Rate Derivatives (Details) - Interest Rate Swap - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2021
Derivative [Line Items]
Derivative, Notional Amount	$ 1,500,000,000
Cash received from interest rate swap unwind	74,835,000
Derivative Instrument Maturity Date 2020, 3 Month LIBOR minus 0.1075%
Derivative [Line Items]
Basis spread		0.1075%
Derivative Instrument Maturity Date 2025, Fixed 1.53%
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Company Pays		1.53%
Derivative Instrument Maturity Date 2022, Fixed 2.733%
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Company Pays		2.733%
Derivative Instrument Maturity Date 2025, Fixed 1.625
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Company Pays		1.625%
Derivative Instrument Maturity Date 2026, Fixed 2.9155%
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Company Pays		2.9155%
Derivative Instrument Maturity Date 2026, Fixed 2.9025%
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Company Pays		2.9025%
Derivative Instrument Maturity Date 2025, Fixed 1.458%
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Company Pays		1.458%
Derivative Instruments Maturing Date 2025, Fixed 1.53% and 1.625% [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 1,000,000,000
Derivative Instrument Notional Amount 2,850,000, 0.5185% Basis Spread | LIBOR
Derivative [Line Items]
Derivative, Notional Amount		$ 2,850,000,000

FAIR VALUE MEASUREMENT - Assets

FAIR VALUE MEASUREMENT - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Carrying Amount
Liabilities:
Debt, fair value	$ 26,509,881	$ 26,562,705
Estimated Fair Value
Liabilities:
Debt, fair value	27,250,461	27,811,011
Fair Value, Inputs, Level 2 [Member] | Carrying Amount | Credit facility debt | CSC Holdings
Liabilities:
Debt, fair value	8,221,097	8,288,000
Fair Value, Inputs, Level 2 [Member] | Carrying Amount | Secured Debt [Member] | CSC Holdings
Liabilities:
Debt, fair value	1,677,985	1,617,506
Fair Value, Inputs, Level 2 [Member] | Carrying Amount | Senior guaranteed notes and senior secured notes | CSC Holdings
Liabilities:
Debt, fair value	8,068,088	8,066,796
Fair Value, Inputs, Level 2 [Member] | Carrying Amount | Senior notes | CSC Holdings
Liabilities:
Debt, fair value	8,424,646	8,415,602
Fair Value, Inputs, Level 2 [Member] | Carrying Amount | Notes payable and supply chain financing | CSC Holdings
Liabilities:
Debt, fair value	118,065	174,801
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value | Credit facility debt | CSC Holdings
Liabilities:
Debt, fair value	8,280,500	8,350,188
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value | Secured Debt [Member] | CSC Holdings
Liabilities:
Debt, fair value	1,753,986	1,692,724
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value | Senior guaranteed notes and senior secured notes | CSC Holdings
Liabilities:
Debt, fair value	8,363,231	8,567,858
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value | Senior notes | CSC Holdings
Liabilities:
Debt, fair value	8,734,561	9,024,990
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value | Notes payable and supply chain financing | CSC Holdings
Liabilities:
Debt, fair value	118,183	175,251
Fair Value Measured on a Recurring Basis | Fair Value, Inputs, Level 1 [Member]
Assets:
Investment securities	2,324,308	2,250,854
Prepaid forward contracts | Fair Value Measured on a Recurring Basis | Fair Value, Inputs, Level 2 [Member]
Assets:
Derivative asset	0	45,653
Liabilities:
Derivative liability	(301,418)	293,506
Interest rate swap contracts | Fair Value Measured on a Recurring Basis | Fair Value, Inputs, Level 2 [Member]
Assets:
Derivative asset	8,252	9,906
Liabilities:
Derivative liability	(183,845)	275,297
Money market funds | Fair Value Measured on a Recurring Basis | Fair Value, Inputs, Level 1 [Member]
Assets:
Money market funds	$ 150,965	$ 50,236

SHARE-BASED COMPENSATION - Narr

SHARE-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Period End Date	Mar. 31, 2021
Share based compensation expense	$ 28,281	$ 27,946
Share based compensation - Unrecognized deferred compensation cost	$ 184,811
Carry Unit Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value (in dollars per unit)	$ 2.10		$ 3.89
Share based compensation expense	$ 759	3,120
Share based compensation - Unrecognized deferred compensation cost	44
2017 LTIP | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense	24,223	20,349
Share based compensation - Unrecognized deferred compensation cost	123,543
2017 LTIP | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense	2,982	3,901
Share based compensation - Unrecognized deferred compensation cost	60,675
2019 LTIP | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense	317	$ 576
Share based compensation - Unrecognized deferred compensation cost	$ 549

SHARE-BASED COMPENSATION - Carr

SHARE-BASED COMPENSATION - Carrying Unit Award Activity (Details) - Carry Unit Plan	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Weighted Average Grant Date Fair Value
Balance at beginning of period, weighted average grant date fair value (in dollars per share) | $ / shares	$ 3.41
Vested weighted average grant date fair value (in dollars per share) | $ / shares	3.80
Balance at end of period, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.99
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares) | shares	6,875,000
Vested (in shares) | shares	(5,375,000)
Ending balance (in shares) | shares	1,500,000

SHARE-BASED COMPENSATION - Stoc

SHARE-BASED COMPENSATION - Stock Option Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Weighted Average Exercise Price Per Share
Exercised, weighted average exercise price per share (in dollars per share)	$ 17.79
Share based compensation expense	$ 28,281,000	$ 27,946,000
Share based compensation - Unrecognized deferred compensation cost	$ 184,811,000
Risk-free interest rate	0.93%
Expected life (in years)	6 years 2 months 4 days
Dividend yield	0.00%
Volatility	32.92%
Grant date fair value	$ 10.77
2017 LTIP
Weighted Average Exercise Price Per Share
Beginning balance (in dollars per share)	25.52
Granted (in dollars per share)	34.78
Forfeited (in dollars per share)	26.10
Ending balance (in dollars per share)	25.64
Options exercisable (in dollars per share)	$ 17.55
Options outstanding, Weighted Average Remaining Contractual Term (in years)	8 years 5 months 15 days	8 years 8 months 8 days
Options exercisable, Weighted Average Remaining Contractual Term (in years)	6 years 9 months 10 days
Options outstanding, Aggregate Intrinsic Value	$ 256,796,000		$ 457,608,000
Options exercisable, Aggregate Intrinsic Value	$ 47,070,000
2017 LTIP | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares)	37,062,146
Granted (in shares)	409,478
Option exercises	104,365
Forfeited (in shares)	(360,778)
Ending balance (in shares)	37,006,481
Options exercisable (in shares)	3,141,750
Weighted Average Exercise Price Per Share
Share based compensation expense	$ 24,223,000	$ 20,349,000
Share based compensation - Unrecognized deferred compensation cost	$ 123,543,000
Expected time (in years) unrecogized compensation costs relating to share based awards will be recognized	2 years 6 months 21 days
2017 LTIP | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted (in shares)	7,330,235
Weighted Average Exercise Price Per Share
Share based compensation expense	$ 2,982,000	3,901,000
Share based compensation - Unrecognized deferred compensation cost	$ 60,675,000
Expected time (in years) unrecogized compensation costs relating to share based awards will be recognized	4 years 10 months 6 days
Grant date fair value	$ 10.65
2019 LTIP | Restricted Stock
Weighted Average Exercise Price Per Share
Share based compensation expense	$ 317,000	$ 576,000
Share based compensation - Unrecognized deferred compensation cost	$ 549,000

SHARE-BASED COMPENSATION - Fair

SHARE-BASED COMPENSATION - Fair Value Assumptions For Stock Options (Details)	3 Months Ended
	Mar. 31, 2021$ / shares
Share-based Payment Arrangement [Abstract]
Risk-free interest rate	0.93%
Expected life (in years)	6 years 2 months 4 days
Dividend yield	0.00%
Volatility	32.92%
Grant date fair value	$ 10.77

AFFILIATE AND RELATED PARTY T_3

AFFILIATE AND RELATED PARTY TRANSACTIONS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Related Party Transaction [Line Items]
Related party expense	$ 2,001	$ 2,642

AFFILIATE AND RELATED PARTY T_4

AFFILIATE AND RELATED PARTY TRANSACTIONS - Revenue and Related Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Related Party Transaction [Line Items]
Revenue	$ 3,406	$ 3,488
Operating expenses:
Programming and other direct costs	(2,228)	(2,189)
Other operating expenses, net	(3,179)	(3,941)
Operating expenses, net	(5,407)	(6,130)
Net charges	(2,001)	(2,642)
Capital Expenditures	$ 10,621	$ 7,225

AFFILIATE AND RELATED PARTY T_5

AFFILIATE AND RELATED PARTY TRANSACTIONS - Amounts Due From and Due to Related Parties (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Treasury Stock, Shares, Acquired	6,066,251		6,629,415
Payments for Repurchase of Common Stock	$ 503,645	$ 726,005
Share based compensation expense	28,281	27,946
Related party expense	$ 2,001	2,642
Stock options | 2017 LTIP
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	409,478
Share based compensation expense	$ 24,223	20,349
Restricted Stock | 2019 LTIP
Related Party Transaction [Line Items]
Share based compensation expense	317	576
CSC Holdings
Related Party Transaction [Line Items]
Cash distributions to parent	501,000	720,350
Intercompany settlement	745	(150,602)
Cash distributions	501,000	$ 720,350
Affiliates
Related Party Transaction [Line Items]
Due to related parties and affiliates	12,698		$ 8,538
Affiliates | Other Related Party
Related Party Transaction [Line Items]
Due from related parties and affiliates	3,795		4,262
Due to related parties and affiliates	1,226		600
Affiliates | Altice Management International
Related Party Transaction [Line Items]
Due to related parties and affiliates	$ 11,472		$ 7,938

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) $ in Thousands	Apr. 06, 2021USD ($)
North Carolina Assets | Subsequent Event
Consideration transfered	$ 310,000

Uncategorized Items - atus-2021

Label	Element	Value
Noncontrolling Interest [Member]
Net Income (Loss) Attributable to Noncontrolling Interest	us-gaap_NetIncomeLossAttributableToNoncontrollingInterest	$ 8,618,000