Segments - Results of Continuing Operations (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021		Jun. 30, 2022	Jun. 30, 2021
Segment Information
Revenue	$ 15,535.0	$ 14,218.0	[1]	$ 29,732.0	$ 27,405.0	[1]
Pre-tax income from continuing operations	1,722.0	912.0	[1]	2,345.0	1,155.0	[1]
Business Segments
Segment Information
Revenue	15,355.0	13,941.0		29,328.0	26,843.0
Pre-tax income from continuing operations	$ 2,577.0	$ 1,949.0		$ 4,342.0	$ 3,274.0
Revenue year-to-year change (as a percent)	10.10%			9.30%
Pre-tax income year-to-year change (as a percent)	32.20%			32.60%
Pre-tax income margin (as a percent)	16.80%	14.00%		14.80%	12.20%
Business Segments | Software
Segment Information
Revenue	$ 6,166.0	$ 5,795.0		$ 11,938.0	$ 10,933.0
Pre-tax income from continuing operations	$ 1,375.0	$ 1,059.0		$ 2,509.0	$ 1,717.0
Revenue year-to-year change (as a percent)	6.40%			9.20%
Pre-tax income year-to-year change (as a percent)	29.90%			46.20%
Pre-tax income margin (as a percent)	22.30%	18.30%		21.00%	15.70%
Business Segments | Consulting
Segment Information
Revenue	$ 4,809.0	$ 4,378.0		$ 9,637.0	$ 8,641.0
Pre-tax income from continuing operations	$ 343.0	$ 270.0		$ 691.0	$ 547.0
Revenue year-to-year change (as a percent)	9.80%			11.50%
Pre-tax income year-to-year change (as a percent)	26.90%			26.30%
Pre-tax income margin (as a percent)	7.10%	6.20%		7.20%	6.30%
Business Segments | Infrastructure
Segment Information
Revenue	$ 4,235.0	$ 3,560.0		$ 7,453.0	$ 6,853.0
Pre-tax income from continuing operations	$ 757.0	$ 489.0		$ 956.0	$ 780.0
Revenue year-to-year change (as a percent)	19.00%			8.80%
Pre-tax income year-to-year change (as a percent)	54.80%			22.50%
Pre-tax income margin (as a percent)	17.90%	13.70%		12.80%	11.40%
Business Segments | Financing
Segment Information
Revenue	$ 146.0	$ 209.0		$ 300.0	$ 417.0
Pre-tax income from continuing operations	$ 102.0	$ 131.0		$ 186.0	$ 229.0
Revenue year-to-year change (as a percent)	(29.90%)			(28.00%)
Pre-tax income year-to-year change (as a percent)	(22.40%)			(18.90%)
Pre-tax income margin (as a percent)	69.70%	63.00%		62.00%	55.00%

[1] Reclassified to reflect discontinued operations presentation.