Relationship with Universal Health Realty Income Trust and Other Related Party Transactions - Additional Information (Detail)		3 Months Ended				9 Months Ended		12 Months Ended
	Jan. 01, 2023	Sep. 30, 2023 USD ($) Facility SquareFoot	Mar. 31, 2023 USD ($) Bed SquareFoot	Sep. 30, 2022 USD ($)	Dec. 31, 2013	Sep. 30, 2023 USD ($) Bed Facility Hospital	Sep. 30, 2022 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) Facility	Dec. 31, 2021 USD ($) Bed	Dec. 31, 2020
Related Party Transaction [Line Items]
Net revenues		$ 3,562,774,000		$ 3,336,027,000		$ 10,578,430,000	$ 9,952,390,000
Lease and rental expense		$ 35,466,000		33,264,000		$ 105,775,000	97,075,000
Number of hospital facilities | Hospital						5
Lessee, Operating Lease, Existence of Option to Extend [true false]						true
Chief Executive Officer
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies						$ 28,000,000
Payments to acquire life insurance policies, net									$ 1,000,000.0
Chief Executive Officer | Scenario Forecast
Related Party Transaction [Line Items]
Payments to acquire life insurance policies, net								$ 1,000,000.0
Chief Executive Officer | Trust Owned by CEO
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies						$ 9,000,000
Minimum
Related Party Transaction [Line Items]
Real estate leases option to extend lease term		5 years				5 years
Lease initial terms		5 years				5 years
Minimum | Chief Executive Officer
Related Party Transaction [Line Items]
Estimated death benefit proceeds						$ 37,000,000
Maximum
Related Party Transaction [Line Items]
Real estate leases option to extend lease term		10 years				10 years
Lease initial terms		10 years				10 years
Acute Care Hospital Services
Related Party Transaction [Line Items]
Net revenues		$ 2,017,288,000		1,919,678,000		$ 5,993,899,000	$ 5,707,510,000
Canyon Creek Behavioral Health
Related Party Transaction [Line Items]
Percentage of annual rental increase on cumulative and compound basis	2.25%
Asset Purchase and Sale Agreement | Subsidiaries
Related Party Transaction [Line Items]
Gain on sale of real estate assets										$ 4,000,000
Relationship with Universal Health Realty Income Trust
Related Party Transaction [Line Items]
Percentage of advisory fee on average invested real estate assets						0.70%	0.70%		0.70%	0.70%	0.70%
Pre-tax share of income from the Trust		100,000		275,000		$ 670,000	$ 882,000
Dividends received from the Trust		567,000		559,000		1,700,000	1,700,000
Carrying value of investment in Trust		7,300,000				7,300,000			$ 8,400,000
Market value of investment in Trust		31,800,000				31,800,000			37,600,000
Financial liability included in debt		78,000,000				78,000,000			81,000,000
Lease and rental expense		$ 5,000,000		5,000,000		$ 15,000,000	15,000,000
Number of square feet to be acquired | SquareFoot		79,500
Notice period on renewal of lease						90 days
Number of free-standing emergency departments to be acquired | Facility		2				2
Number of square feet to be constructed | SquareFoot			86,000
Number of beds available in acute care hospital | Bed			170
Percentage of master lease rentable square feet		100.00%	68.00%
Relationship with Universal Health Realty Income Trust | Minimum
Related Party Transaction [Line Items]
Lease and rental expense		$ 624,000	$ 1,300,000
Relationship with Universal Health Realty Income Trust | Minimum | Limited Liability Companies
Related Party Transaction [Line Items]
Non-controlling ownership interests by subsidiaries		95.00%				95.00%
Relationship with Universal Health Realty Income Trust | Maximum | Limited Liability Companies
Related Party Transaction [Line Items]
Non-controlling ownership interests by subsidiaries		100.00%				100.00%
Relationship with Universal Health Realty Income Trust | Aiken, South Carolina | Behavioral Health Care Facility
Related Party Transaction [Line Items]
Lease and rental expense						$ 2,700,000	2,600,000
Notice period on renewal of lease						270 days
Period of rights of refusal to leased facilities						30 days
Number of bed available in behavioral health care facility | Bed						100
Relationship with Universal Health Realty Income Trust | Aiken Regional Medical Center
Related Party Transaction [Line Items]
Lease rent receivable									3,900,000
Relationship with Universal Health Realty Income Trust | Canyon Creek Behavioral Health
Related Party Transaction [Line Items]
Lease rent receivable									1,800,000
Relationship with Universal Health Realty Income Trust | Aiken Regional Medical Center and Canyon Creek Behavioral Health
Related Party Transaction [Line Items]
Initial lease term on property										12 years
Real estate leases option to extend lease term										7 years
Lease initial terms										5 years
Lease rent receivable									$ 5,700,000
Number of facilities leased | Facility									2
Percentage of annual rental increase on cumulative and compound basis						2.25%
Lease Expiration Date										Dec. 31, 2033
Lessee, Operating Lease, Existence of Option to Extend [true false]										true
Relationship with Universal Health Realty Income Trust | Aiken Regional Medical Center and Canyon Creek Behavioral Health | Bonus Rental
Related Party Transaction [Line Items]
Lease revenue						$ 0
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries
Related Party Transaction [Line Items]
Cash received for sale of real estate asset										$ 4,100,000
Gain on sale of real estate assets										68,400,000
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Inland Valley Campus of Southwest Healthcare System | Wildomar, California
Related Party Transaction [Line Items]
Fair market value of real estate assets received										79,600,000
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Aiken Regional Medical Center | Aiken South Carolina
Related Party Transaction [Line Items]
Fair market value of real estate assets sold										$ 57,700,000
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Aiken Regional Medical Center | Aiken South Carolina | Behavioral Health Care Facility
Related Party Transaction [Line Items]
Number of beds available in acute care hospital | Bed										62
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Aiken Regional Medical Center | Aiken South Carolina | Acute Care Hospital Services
Related Party Transaction [Line Items]
Number of beds available in acute care hospital | Bed										211
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Canyon Creek Behavioral Health | Temple, Texas
Related Party Transaction [Line Items]
Fair market value of real estate assets sold										$ 26,000,000
Relationship with Universal Health Realty Income Trust | Asset Purchase and Sale Agreement | Subsidiaries | Aiken Regional Medical Center and Canyon Creek Behavioral Health
Related Party Transaction [Line Items]
Fair market value of real estate assets sold										$ 83,700,000
Relationship with Universal Health Realty Income Trust | Other Related Party Transactions
Related Party Transaction [Line Items]
Trust outstanding shares held, percentage		5.70%				5.70%
Relationship with Universal Health Realty Income Trust | Advisory Fee
Related Party Transaction [Line Items]
Net revenues		$ 1,300,000		1,300,000		$ 4,000,000.0	3,800,000
Premier, Inc. | Other (Income) Expense, Net
Related Party Transaction [Line Items]
Dividend		$ 470,000		$ 470,000		1,400,000	$ 1,400,000
Premier, Inc. | Group Purchasing Organization Agreement | Restricted Stock
Related Party Transaction [Line Items]
Shares vesting period					7 years
Shares vesting period start year					2014
Shares vesting period end year					2020
Market value of retained vested shares						$ 48,000,000			$ 78,000,000