Acquisitions and Dispositions - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($) Hospital	Jun. 30, 2024 USD ($) Hospital
Business Acquisition [Line Items]
Proceeds from sale of business	$ 167	$ 311
Pretax gain (loss) before tax	(2)	213
Real Estate and Other Investments [Member]
Business Acquisition [Line Items]
Proceeds from sale of business	11	14
Healthcare Entity [Member]
Business Acquisition [Line Items]
Aggregate purchase price	136	81
Hospital Facility [Member]
Business Acquisition [Line Items]
Aggregate purchase price	$ 190	$ 50
Number of hospitals purchased | Hospital	2	2
Proceeds from sale of business	$ 156	$ 297
Number of hospitals sold | Hospital	1	1