FAIR VALUE MEASUREMENT (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents for each of these hierarchy levels, the Company's financial assets and financial liabilities that are measured at fair value on a recurring basis:

	Fair Value Hierarchy	June 30, 2018		December 31, 2017
Assets:
Money market funds	Level I	$	218,940	$	5,949
Investment securities pledged as collateral	Level I	1,409,361		1,720,357
Prepaid forward contracts	Level II	110,630		52,545
Interest rate swap contracts	Level II	369		—
Liabilities:
Prepaid forward contracts	Level II	9,623		162,049
Interest rate swap contracts	Level II	123,470		77,902
Contingent consideration related to 2017 acquisitions	Level III	2,233		32,233

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

		June 30, 2018				December 31, 2017
	Fair Value Hierarchy	Carrying Amount (a)		Estimated Fair Value		Carrying Amount (a)		Estimated Fair Value
CSC Holdings debt instruments:
Credit facility debt	Level II	$	4,435,479	$	4,470,000	$	3,393,306	$	3,435,000
Collateralized indebtedness	Level II	1,392,648		1,338,105		1,349,474		1,305,932
Senior guaranteed notes	Level II	3,283,795		3,195,375		2,291,185		2,420,000
Senior notes and debentures	Level II	6,107,472		6,727,849		6,409,889		7,221,846
Notes payable	Level II	36,161		35,962		56,956		55,289
Cablevision senior notes:
Senior notes and debentures	Level II	1,072,340		1,165,034		1,818,115		1,931,239
Cequel debt instruments:
Cequel credit facility debt	Level II	1,244,153		1,252,350		1,250,217		1,258,675
Senior secured notes	Level II	2,572,438		2,535,500		2,570,506		2,658,930
Senior notes	Level II	2,804,435		2,942,800		2,770,737		2,983,615
Notes payable	Level II	36,356		36,356		8,946		8,946
		$	22,985,277	$	23,699,331	$	21,919,331	$	23,279,472

(a) Amounts are net of unamortized deferred financing costs, premiums and discounts.