Spectrum repacking reimbursements and other, net - Schedule of Non-Cash Impairment Charges (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unusual or Infrequent Items, or Both [Abstract]
Reimbursement of spectrum repacking	$ (16,974)	$ (7,400)	$ 0
Property and equipment (gains) impairments	(2,880)	(5,989)	2,183
Impairment charges related to assets held-for-sale	9,063	0	0
Contract termination and other costs related to national sales	5,456	0	0
Lease exit and other charges	0	551	1,350
Hurricane related losses, net	0	1,137	896
Total spectrum repacking reimbursements and other, net	$ (5,335)	$ (11,701)	$ 4,429