Consolidated Statements Of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenues	$ 4,744	$ 4,243	$ 13,730	$ 12,468
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	2,947	2,647	8,574	8,009
Selling, general and administrative expenses	924	804	2,632	2,226
Depreciation and amortization expense	144	138	430	407
Income from operations	729	603	2,094	1,649
Other income (expense), net:
Interest income	7	27	23	105
Interest expense	(3)	(6)	(7)	(21)
Foreign currency exchange gains (losses), net	(3)	(1)	(19)	(105)
Other, net	1	1	(1)	1
Total other income (expense), net	2	21	(4)	(20)
Income before provision for income taxes	731	624	2,090	1,629
Provision for income taxes	(187)	(276)	(531)	(552)
Income (Loss) from Equity Method Investments	0	0	2	(1)
Net income	$ 544	$ 348	$ 1,561	$ 1,076
Basic earnings per share (usd per share)	$ 1.04	$ 0.64	$ 2.96	$ 1.98
Diluted earnings per share (usd per share)	$ 1.03	$ 0.64	$ 2.96	$ 1.98
Weighted average number of common shares outstanding - Basic (shares)	525	542	527	543
Dilutive effect of shares issuable under stock-based compensation plans (shares)	1	1	1	0
Weighted average number of common shares outstanding - Diluted (shares)	526	543	528	543
Restructuring Charges	$ 0	$ 51	$ 0	$ 177