Business and Summary of Significant Accounting Policies - Other Assets and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Summary Of Business And Significant Accounting Policies [Line Items]
Impairment of intangible assets	$ 0	$ 0
Provision for asset impairment	0	57,550,000	$ 14,391,000
Other (Income) Expense, Net
Summary Of Business And Significant Accounting Policies [Line Items]
Provision for asset impairment		58,000,000	$ 14,000,000
Commercial Insurance Subsidiary
Summary Of Business And Significant Accounting Policies [Line Items]
Statutorily required capital reserves	113,000,000	116,000,000
Universal Health Realty Income Trust
Summary Of Business And Significant Accounting Policies [Line Items]
Investments	7,000,000	8,000,000
Premier, Inc.
Summary Of Business And Significant Accounting Policies [Line Items]
Investments	$ 50,000,000	$ 78,000,000