FAIR VALUE MEASUREMENT - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Carrying Amount
Liabilities:
Debt, fair value	$ 26,789,276	$ 26,562,705
Estimated Fair Value
Liabilities:
Debt, fair value	27,480,125	27,811,011
Fair Value, Inputs, Level 2 [Member] \| Carrying Amount \| Credit facility debt \| CSC Holdings
Liabilities:
Debt, fair value	7,954,232	8,288,000
Fair Value, Inputs, Level 2 [Member] \| Carrying Amount \| Secured Debt [Member] \| CSC Holdings
Liabilities:
Debt, fair value	1,687,530	1,617,506
Fair Value, Inputs, Level 2 [Member] \| Carrying Amount \| Senior guaranteed notes and senior secured notes \| CSC Holdings
Liabilities:
Debt, fair value	8,075,370	8,066,796
Fair Value, Inputs, Level 2 [Member] \| Carrying Amount \| Senior notes \| CSC Holdings
Liabilities:
Debt, fair value	8,932,157	8,415,602
Fair Value, Inputs, Level 2 [Member] \| Carrying Amount \| Notes payable and supply chain financing \| CSC Holdings
Liabilities:
Debt, fair value	139,987	174,801
Fair Value, Inputs, Level 2 [Member] \| Estimated Fair Value \| Credit facility debt \| CSC Holdings
Liabilities:
Debt, fair value	8,010,813	8,350,188
Fair Value, Inputs, Level 2 [Member] \| Estimated Fair Value \| Secured Debt [Member] \| CSC Holdings
Liabilities:
Debt, fair value	1,752,165	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	8,361,375	8,567,858
Fair Value, Inputs, Level 2 [Member] \| Estimated Fair Value \| Senior notes \| CSC Holdings
Liabilities:
Debt, fair value	9,215,990	9,024,990
Fair Value, Inputs, Level 2 [Member] \| Estimated Fair Value \| Notes payable and supply chain financing \| CSC Holdings
Liabilities:
Debt, fair value	139,782	175,251
Fair Value Measured on a Recurring Basis \| Fair Value, Inputs, Level 1 [Member]
Assets:
Investment securities		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	400,258	293,506
Interest rate swap contracts \| Fair Value Measured on a Recurring Basis \| Fair Value, Inputs, Level 2 [Member]
Assets:
Derivative asset	3,967	9,906
Liabilities:
Derivative liability	189,891	275,297
Money market funds \| Fair Value Measured on a Recurring Basis \| Fair Value, Inputs, Level 1 [Member]
Assets:
Money market funds	$ 115,486	$ 50,236

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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