Debt Instrument, Increase in Line of Credit Facility

No definition available.

Name:	atus_DebtInstrumentIncreaseinLineofCreditFacility
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Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit, Covenant Compliance, Cash Proceeds Requirement of Certain Assets Sales, Reinvestment Rights and Other

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Line of Credit, Covenant Compliance, Excess Cash Flow, Percentage Required When Minimum Leverage Ratio is Fulfilled

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Line of Credit, Covenant Compliance, Excess Cash Flow, Percentage Required When Minimum Leverage Ratio is Not Met

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Covenant, Leverage Ratio

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Covenant, Minimum Undrawn Letters of Credit

+ References

No definition available.

+ Details

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Namespace Prefix:	atus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Periodic Payment, Percentage of Principal

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum Debt Leverage Ratio Required for Zero Percent of Excess Cash Flow Obligation to Prepay Debt

+ References

No definition available.

+ Details

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Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Write-off the deferred financing costs and the unamortized discount.

+ References

No definition available.

+ Details

Name:	atus_WriteOffOfDeferredDebtIssuanceCotsAndUnamortizedDiscount
Namespace Prefix:	atus_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of paid and unpaid cash dividends declared for classes of stock, for example, but not limited to, common and preferred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the required periodic payment applied to principal.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for a long-term debt where the holder has highest claim on the entity's asset in case of bankruptcy or liquidation during the period.

+ References

+ Details

Name:	us-gaap_RepaymentsOfSeniorDebt
Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=atus_CSCHoldings5.5NotesdueApril152027Member
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- Details

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Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Period Type:

- Details

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DEBT - CSC Holdings Credit Facilities (Details)			1 Months Ended		3 Months Ended	12 Months Ended
DEBT - CSC Holdings Credit Facilities (Details)	Mar. 15, 2017 USD ($)	Apr. 26, 2016 USD ($)	Apr. 30, 2017 USD ($)	Oct. 31, 2016 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 21, 2016 USD ($)
Debt Instrument [Line Items]
Principal Amount						$ 4,693,675,000
Credit facility						4,643,523,000	$ 3,444,790,000
Repayments of lines of credit		$ 1,477,200,000
Redemption of debt amount						1,729,400,000	0
Loss on extinguishment of debt and write-off of deferred financing costs	$ 18,976,000					600,240,000	127,649,000
Cash distributions to shareholders					$ 839,700,000	840,035,000	445,176,000
Senior Notes
Debt Instrument [Line Items]
Principal Amount						16,289,245,000
CSC Holdings 8.625% Notes due September 15, 2017 [Member] \| Senior Notes
Debt Instrument [Line Items]
Redemption of debt amount			$ 500,000,000
5.5% Notes due April 15, 2027 \| Senior Notes
Debt Instrument [Line Items]
Principal Amount						$ 1,310,000,000		$ 1,310,000,000
Stated interest rate						5.50%		5.50%
Deferred financing costs								$ 5,575,000
8.625% Notes due September 15, 2017 \| Senior Notes
Debt Instrument [Line Items]
Principal Amount						$ 0
Stated interest rate			8.625%			8.625%
CSC Credit Facilities
Debt Instrument [Line Items]
Percentage of proceeds from asset sales required to pay down term loans						100.00%
Percentage of excess cash flow required when minimum leverage ratio is not met						50.00%
Percentage of excess cash flow required to pay down term loans when minimum leverage ratio is fulfilled						0.00%
Minimum debt leverage ratio required for zero percent of excess cash flow obligation to prepay debt						4.5
Line of credit facility, covenant, leverage ratio						5.0
Line of credit facility, covenant, minimum undrawn letters of credit						$ 15,000,000
Revolving Credit Facility \| CSC Holdings Revolving Credit Facility
Debt Instrument [Line Items]
Principal Amount						450,000,000
Credit facility						425,488,000	145,013,000
Line of credit facility, aggregate principal amount									$ 2,300,000,000
Repayments of lines of credit						1,075,256,000
Proceeds from credit facility debt					$ 500,000,000	1,350,000,000
Cash distributions to shareholders						$ 500,000,000
Line of credit facility periodic payment, percentage of principal						0.25%
Line of credit facility, periodic payment amount						$ 7,500,000
Revolving Credit Facility \| CSC Holdings Revolving Credit Facility \| Alternate Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate						2.25%
Revolving Credit Facility \| CSC Holdings Revolving Credit Facility \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate						3.25%
Term Loan \| CSC Holdings Term Loan Facility
Debt Instrument [Line Items]
Principal Amount	3,000,000,000					$ 2,985,000,000
Credit facility						2,967,818,000	$ 2,486,874,000
Line of credit facility, aggregate principal amount						3,000,000,000
Write-off the deferred financing costs and the unamortized discount				$ 102,894,000
Deferred financing costs						7,249,000
Issue Discount						$ 6,250,000
Line of credit facility, increase in borrowing capacity	$ 500,000,000
Repayments of lines of credit			$ 2,493,750,000
Term Loan \| CSC Holdings Term Loan Facility \| Alternate Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate						1.25%
Term Loan \| CSC Holdings Term Loan Facility \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate						2.25%