Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Property and equipment		$ 7	$ 6
Deferred site rental receivable		7	7
Total deferred income tax liabilities		14	13
Intangible assets		3	3
Net operating loss carryforwards	[1]	15	18
Straight-line rent expense liability		3	3
Accrued liabilities		6	5
Other		2	2
Valuation allowances		0	0
Total deferred income tax assets, net		29	31
Net deferred income tax assets (liabilities)		$ 15	$ 18

[1] Balance results from the Company's foreign NOLs. Due to the Company's REIT status, no federal or state NOLs result in the Company recording a deferred income tax asset. See further discussion surrounding the Company's NOL balances below.