CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	$ (98,004)	$ (479,939)	$ (226,953)	$ (556,127)
Defined benefit pension plans:
Unrecognized actuarial gain (loss)	(359)	(4,333)	4,192	(4,333)
Applicable income taxes	97	1,733	(1,131)	1,733
Unrecognized gain (loss) arising during period, net of income taxes	(262)	(2,600)	3,061	(2,600)
Settlement loss included in other expense, net	258	389	864	389
Applicable income taxes	(70)	(156)	(234)	(156)
Settlement loss included in other expense, net, net of income taxes	188	233	630	233
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	914	0	914	0
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(338)	0	(338)	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	576	0	576	0
Other comprehensive gain (loss)	502	(4,284)	4,267	(4,284)
Comprehensive loss	(97,502)	(484,223)	(222,686)	(560,411)
Comprehensive loss (income) attributable to noncontrolling interests	149	(365)	147	(602)
Comprehensive loss attributable to Altice USA, Inc. stockholders	(97,353)	(484,588)	(222,539)	(561,013)
Customer Relationships [Member]
Defined benefit pension plans:
Settlement loss included in other expense, net	0	(3,195)	0	(3,195)
Applicable income taxes	0	1,278	0	1,278
Settlement loss included in other expense, net, net of income taxes	$ 0	$ (1,917)	$ 0	$ (1,917)