Leases - Schedule of Underlying Assets under Operating Leases (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	$ 7,219,339
Less: accumulated depreciation	(4,889,425)
Underlying assets under operating leases, net	2,329,914
Land
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	26,672
Building and Improvements
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	332,158
Poles
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	255,103
Fiber
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	2,594,530
Equipment
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	202
Copper
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	3,756,760
Conduit
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	89,768
Tower assets
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	127,289
Capital lease assets
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	10,276
Other assets
Lessor Lease Description [Line Items]
Underlying assets under operating leases, gross	$ 26,581