Acquisitions and Dispositions of Businesses - Completed Dispositions (Details) $ in Millions		3 Months Ended
	Oct. 30, 2025 USD ($)	Mar. 31, 2026 USD ($) disposition	Mar. 31, 2025 USD ($) disposition
Business Combination [Line Items]
Number of dispositions | disposition		0	0
Gain on disposition of business		$ 20	$ 0
Loss on disposition of business		$ 0	$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | NFP Intermediate Holdings A Corp.
Business Combination [Line Items]
Purchase price	$ 2,300
Pre-tax gain	1,200
Intangible assets, net	760
Goodwill	$ 398