Relationship with Universal Health Realty Income Trust and Related Party Transactions - Additional Information (Detail)	3 Months Ended				12 Months Ended
	Mar. 31, 2021 USD ($) Hospital Bed Lease Facility $ / shares	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($) Hospital	Dec. 31, 2013	Dec. 31, 2020 USD ($)	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Net revenues	$ 3,012,987,000		$ 2,829,667,000
Number of hospital facilities | Hospital	3
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				$ 1,100,000
Chief Executive Officer | Trust Owned by CEO
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies	$ 9,000,000
Southwest Healthcare System, Inland Valley Campus
Related Party Transaction [Line Items]
End of Lease Term	2021-12
Minimum
Related Party Transaction [Line Items]
Lease initial terms	5 years
Minimum | Chief Executive Officer
Related Party Transaction [Line Items]
Estimated death benefit proceeds	$ 37,000,000
Maximum
Related Party Transaction [Line Items]
Lease initial terms	10 years
Relationship with Universal Health Realty Income Trust
Related Party Transaction [Line Items]
Trust outstanding shares held, percentage	5.70%
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	$ 300,000		$ 300,000
Dividends received from the Trust	547,000		540,000
Carrying value of investment in Trust	5,100,000				$ 5,400,000
Market value of investment in Trust	$ 53,400,000				50,600,000
Lease renewal period, years	5 years
Rent expense under operating leases	$ 4,000,000		$ 4,000,000
Notice period on renewal of lease	90 days
Period of rights of refusal to leased facilities	180 days
Number of hospital facilities | Hospital	3		3
Number of free-standing emergency departments to be acquired | Facility	2
Relationship with Universal Health Realty Income Trust | Behavioral Health Care Facility
Related Party Transaction [Line Items]
Lease initial terms	20 years
Lease renewal period, years	10 years
Number of triple net lease | Lease	5
Relationship with Universal Health Realty Income Trust | Clive, Iowa. | Behavioral Health Care Facility
Related Party Transaction [Line Items]
Number of bed available in behavioral health care facility | Bed	100
Relationship with Universal Health Realty Income Trust | Minimum
Related Party Transaction [Line Items]
Lease initial terms	13 years
Relationship with Universal Health Realty Income Trust | Minimum | Limited Liability Companies
Related Party Transaction [Line Items]
Non-controlling ownership interests by subsidiaries	95.00%
Relationship with Universal Health Realty Income Trust | Maximum
Related Party Transaction [Line Items]
Lease initial terms	15 years
Relationship with Universal Health Realty Income Trust | Maximum | Limited Liability Companies
Related Party Transaction [Line Items]
Non-controlling ownership interests by subsidiaries	100.00%
Relationship with Universal Health Realty Income Trust | Advisory Fee
Related Party Transaction [Line Items]
Net revenues	$ 1,100,000		$ 1,000,000.0
Premier, Inc.
Related Party Transaction [Line Items]
Cash dividend declared per share | $ / shares	$ 0.19
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	$ 76,000,000				$ 78,000,000
Premier, Inc. | Other (Income) Expense, Net
Related Party Transaction [Line Items]
Dividend		$ 400,000
Premier, Inc. | Other (Income) Expense, Net | ASU 2016-01
Related Party Transaction [Line Items]
Unrealized gain	$ 2,000,000