Goodwill and Intangible Assets - Additional Information (Detail) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2019 USD ($)	Jan. 31, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2016 USD ($) market	Dec. 31, 2018 USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 836,289		$ 836,289			$ 834,855
Proceeds from the sale of intangible assets					0	$ 53,693
Amortization expense related to intangible assets			20,200	$ 22,700	$ 40,500	$ 45,500
Finite-lived intangible assets, remaining amortization period					3 years 4 months 30 days
Patents currently in process			$ 300		$ 300
Spectrum Licenses
Finite-Lived Intangible Assets [Line Items]
Number of mid-sized metropolitan markets | market							40
Lease agreements term							7 years
Intangible assets acquired							$ 31,300
Spectrum Leases | Verizon | Spectrum Licenses
Finite-Lived Intangible Assets [Line Items]
Proceeds from the sale of intangible assets		$ 55,000
Extinguishment of liability		(27,900)
Indefinite-lived intangible assets, written off		31,300
Regulatory costs		1,200
Gain on sale		$ 50,400
Crowd Storage, Inc.
Finite-Lived Intangible Assets [Line Items]
Goodwill addition associated with the acquisition of CrowdStorage					$ 400
Technology asset class | Crowd Storage, Inc.
Finite-Lived Intangible Assets [Line Items]
Definite-lived intangible assets acquired	$ 1,800