Business Combinations - Additional Information (Details) $ / shares in Units, $ in Millions			3 Months Ended	6 Months Ended
	Jun. 30, 2025 USD ($) $ / shares	Jun. 10, 2025 USD ($) $ / shares	Sep. 30, 2025 USD ($) $ / shares	Jun. 30, 2025 USD ($) Acquisition $ / shares	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($) $ / shares	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Business Acquisition [Line Items]
Number of acquisitions | Acquisition				29
Cash paid	$ 1
Common stock, par value | $ / shares	$ 0.1			$ 0.1		$ 0.1
Total revenues related to acquisitions				$ 18
Income before income taxes related to acquisitions				3
Measurement period adjustment, total net assets				5
Measurement period adjustment, goodwill				5
Estimated acquisition earn-out payables	$ 151			151	$ 143	$ 167	$ 169	$ 203	$ 249
Maximum future contingency payments acquisitions	429			429
Other Noncurrent Liabilities
Business Acquisition [Line Items]
Estimated acquisition earn-out payables	88			88
Accounts payable
Business Acquisition [Line Items]
Estimated acquisition earn-out payables	63			$ 63
Business Combinations - Stock Deals
Business Acquisition [Line Items]
Number of acquisitions | Acquisition				9
Assets and Assumed Certain Liabilities
Business Acquisition [Line Items]
Number of acquisitions | Acquisition				13
Book of Business Purchases
Business Acquisition [Line Items]
Number of acquisitions | Acquisition				7
RSC Topco, Inc.
Business Acquisition [Line Items]
Merger consideration shares amount		$ 1,300
Common stock, par value | $ / shares		$ 0.1
RSC Topco, Inc. | Scenario, Forecast
Business Acquisition [Line Items]
Aggregate purchase price			$ 9,825
Net merger consideration payable			9,400
Cash paid			8,100
Merger consideration shares amount			$ 1,300
Common stock, par value | $ / shares			$ 0.1
GRP Holdco Limited
Business Acquisition [Line Items]
Maximum potential earn-out amount	$ 0			$ 0