DEBT - Cequel Credit Facilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Line of Credit Facility [Line Items]
Loss on extinguishment of debt and write-off of deferred financing costs	$ 0	$ 250,489	$ 51,712	$ 250,489
Principal amount	$ 26,917,870		$ 26,917,870		$ 26,940,911