Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,452,989	$ 1,484,407
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,446,324	2,495,367
Operating Segments | Wireless
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,039,211	1,101,716
Operating Segments | Cable
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	220,519	218,471
Operating Segments | Wireline
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	116,390	115,282
Operating Segments | Other Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,070,204	1,059,898
Intersegment Eliminations
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ (993,335)	$ (1,010,960)