Revenues (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Revenue Recognition Non-cancelable Lease Term for Wireless Tenants		five to 15 years
Revenue Recognition for Fiber Solutions Tenants		three to 20 years
Revenue, Performance Obligation, Description of Payment Terms		45 to 60 days
Revenue, Remaining Performance Obligation, Amount		$ 2,300
Revenue Recognized on Deferred Revenues		220	$ 200
Contracted Amounts Receivable from Customers, remaining six months	[1]	2,136
Contracted Amounts Receivable from Customers, in Two Years	[1]	3,973
Contracted Amounts Receivable from Customers, in Three Years	[1]	3,770
Contracted Amounts Receivable from Customers, in Four Years	[1]	3,534
Contracted Amounts Receivable from Customers, in Five Years	[1]	2,873
Contracted Amounts Receivable from Customers, Thereafter	[1]	7,568
Contracted Amounts Receivable from Customers, Total	[1]	23,854
Deferred Revenue [Domain]
Deferred Revenue		1,400
Other Current Assets [Member]
Deferred Revenue		$ 107

[1] Based on the nature of the contract, site rental contracts are accounted for pursuant to relevant lease accounting (ASC 842) or revenue accounting (ASC 606) guidance. Excludes amounts related to services, as those contracts generally have a duration of one year or less.