Business and Summary of Significant Accounting Policies - Other Assets and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary Of Business And Significant Accounting Policies [Line Items]
Impairment of intangible assets	$ 0	$ 0	$ 0
Provision for asset impairment	0	0	57,550,000
Other (Income) Expense, Net
Summary Of Business And Significant Accounting Policies [Line Items]
Provision for asset impairment			$ 58,000,000
Commercial Insurance Subsidiary
Summary Of Business And Significant Accounting Policies [Line Items]
Statutorily required capital reserves	118,000,000	113,000,000
Universal Health Realty Income Trust
Summary Of Business And Significant Accounting Policies [Line Items]
Investments	6,000,000	7,000,000
Premier, Inc.
Summary Of Business And Significant Accounting Policies [Line Items]
Investments	$ 47,000,000	$ 50,000,000