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Acquisitions & Divestitures - Purchase Price Allocation (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Acquisitions
Goodwill	$ 59,416	$ 60,178	$ 55,949
2024 Acquisitions
Acquisitions
Current assets	35
Property, plant and equipment/noncurrent assets	3
Goodwill	207
Total assets acquired	319
Current liabilities	24
Noncurrent liabilities	16
Total liabilities assumed	41
Total purchase price	278
2024 Acquisitions \| Client relationships
Acquisitions
Intangible assets	$ 36
2024 Acquisitions \| Client relationships \| Minimum
Acquisitions
Weighted average useful life	1 year
2024 Acquisitions \| Client relationships \| Maximum
Acquisitions
Weighted average useful life	7 years
2024 Acquisitions \| Completed technology
Acquisitions
Intangible assets	$ 37
Weighted average useful life	7 years
2024 Acquisitions \| Trademarks
Acquisitions
Intangible assets	$ 1
Weighted average useful life	3 years