Revenue Recognition - Revenue by Category (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 151,732
Wireless
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	109,159
Cable
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	30,680
Wireline
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11,893
Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	161,816
Operating Segments | Wireless service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	89,760
Operating Segments | Wireless equipment
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	17,374
Operating Segments | Business, residential and enterprise
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	39,822
Operating Segments | Tower
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	9,607
Operating Segments | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,253
Operating Segments | Wireless
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	110,398
Operating Segments | Wireless | Wireless service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	89,760
Operating Segments | Wireless | Wireless equipment
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	17,374
Operating Segments | Wireless | Business, residential and enterprise
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Operating Segments | Wireless | Tower
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,896
Operating Segments | Wireless | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	368
Operating Segments | Cable
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	31,711
Operating Segments | Cable | Wireless service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Operating Segments | Cable | Wireless equipment
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Operating Segments | Cable | Business, residential and enterprise
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	29,131
Operating Segments | Cable | Tower
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,046
Operating Segments | Cable | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,534
Operating Segments | Wireline
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	19,707
Operating Segments | Wireline | Wireless service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Operating Segments | Wireline | Wireless equipment
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Operating Segments | Wireline | Business, residential and enterprise
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10,691
Operating Segments | Wireline | Tower
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,665
Operating Segments | Wireline | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,351
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(10,084)
Intersegment Eliminations | Wireless
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1,239)
Intersegment Eliminations | Cable
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1,031)
Intersegment Eliminations | Wireline
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ (7,814)