Revenue Recognition (Revenue Categories) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 122,336	$ 122,428	$ 120,741
Service
Disaggregation of Revenue [Line Items]
Total operating revenues	100,135	99,649	97,831
Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	68,041	65,744	62,674
Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	18,064	20,274	21,891
IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	11,212	10,455	9,669
Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	1,518	1,802	2,069
Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	1,300	1,374	1,528
Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	22,201	22,779	22,910
Operating Segments
Disaggregation of Revenue [Line Items]
Total operating revenues	121,884	121,970	120,211
Operating Segments | Communications
Disaggregation of Revenue [Line Items]
Total operating revenues	117,652	118,038	117,067
Operating Segments | Communications | Mobility
Disaggregation of Revenue [Line Items]
Total operating revenues	85,255	83,982	81,780
Operating Segments | Communications | Mobility | Service
Disaggregation of Revenue [Line Items]
Total operating revenues	65,373	63,175	60,499
Operating Segments | Communications | Mobility | Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	65,373	63,175	60,499
Operating Segments | Communications | Mobility | Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	19,882	20,807	21,281
Operating Segments | Communications | Business Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	18,819	20,883	22,538
Operating Segments | Communications | Business Wireline | Service
Disaggregation of Revenue [Line Items]
Total operating revenues	18,064	20,274	21,891
Operating Segments | Communications | Business Wireline | Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	18,064	20,274	21,891
Operating Segments | Communications | Business Wireline | IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	755	609	647
Operating Segments | Communications | Consumer Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	13,578	13,173	12,749
Operating Segments | Communications | Consumer Wireline | Service
Disaggregation of Revenue [Line Items]
Total operating revenues	13,578	13,173	12,749
Operating Segments | Communications | Consumer Wireline | Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	11,212	10,455	9,669
Operating Segments | Communications | Consumer Wireline | Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	1,265	1,508	1,746
Operating Segments | Communications | Consumer Wireline | Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	1,101	1,210	1,334
Operating Segments | Communications | Consumer Wireline | Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America Business Segment
Disaggregation of Revenue [Line Items]
Total operating revenues	4,232	3,932	3,144
Operating Segments | Latin America Business Segment | Service
Disaggregation of Revenue [Line Items]
Total operating revenues	2,668	2,569	2,162
Operating Segments | Latin America Business Segment | Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	2,668	2,569	2,162
Operating Segments | Latin America Business Segment | Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America Business Segment | IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America Business Segment | Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America Business Segment | Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America Business Segment | Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	1,564	1,363	982
Corporate
Disaggregation of Revenue [Line Items]
Total operating revenues	452	458	530
Corporate | Service
Disaggregation of Revenue [Line Items]
Total operating revenues	452	458	530
Corporate | Wireless Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	13
Corporate | Business Service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Corporate | IP Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Corporate | Legacy Voice and Data [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	253	294	323
Corporate | Other Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	199	164	194
Corporate | Other Capitalized Property Plant and Equipment [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 0	$ 0	$ 0