Revenue Recognition - Disaggregation of Revenue by Major Products and Service Offerings (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue by Major Products/Service Offerings
Total Revenue	$ 14,752	$ 14,107	$ 44,479	$ 43,840
Operating Segments
Revenue by Major Products/Service Offerings
Total Revenue	14,685	14,037	44,287	43,365
Other
Revenue by Major Products/Service Offerings
Revenue	67	70	192	475
Software | Operating Segments
Revenue by Major Products/Service Offerings
Total Revenue	6,265	5,811	18,794	17,749
Consulting | Operating Segments
Revenue by Major Products/Service Offerings
Total Revenue	4,963	4,700	14,938	14,337
Infrastructure | Operating Segments
Revenue by Major Products/Service Offerings
Total Revenue	3,272	3,352	9,988	10,805
Financing | Operating Segments
Revenue by Major Products/Service Offerings
Total Revenue	186	174	566	474
Hybrid Platform & Solutions | Software | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	4,506	4,172	13,350	12,641
Transaction Processing | Software | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	1,759	1,640	5,444	5,107
Business Transformation | Consulting | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	2,291	2,165	6,869	6,646
Application Operations | Consulting | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	1,710	1,593	5,204	4,865
Technology Consulting | Consulting | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	961	943	2,865	2,826
Hybrid Infrastructure | Infrastructure | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	1,943	1,931	5,912	6,392
Infrastructure Support | Infrastructure | Operating Segments
Revenue by Major Products/Service Offerings
Revenue	$ 1,329	$ 1,421	$ 4,076	$ 4,413