Debt and Other Obligations Extinguishment of Debt (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021
Extinguishment of Debt [Line Items]
Principal amount				$ 1,250
Cash paid	[1]			1,274
Gains (losses) on retirement of long-term obligations		$ 0	$ (1)	(26)	[2]	$ (144)
3.849% Secured Notes [Member]
Extinguishment of Debt [Line Items]
Principal amount				1,000
Cash paid	[1]			1,022
Gains (losses) on retirement of long-term obligations	[2]			23
2018 Tower Revenue Notes 3.720% due 2043 [Member]
Extinguishment of Debt [Line Items]
Principal amount				250
Cash paid	[1]			252
Gains (losses) on retirement of long-term obligations	[2]			$ 3

[1] Exclusive of accrued interest.

[2] Inclusive of the write off of respective deferred financing costs.