Business and Summary of Significant Accounting Policies - Additional Information (Detail) shares in Millions			1 Months Ended	3 Months Ended									12 Months Ended
		Oct. 01, 2018 USD ($)	May 31, 2016 USD ($) Hospital	Dec. 31, 2018 USD ($) Facility	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2013	Dec. 31, 2018 USD ($) Hospital Facility shares	Dec. 31, 2017 USD ($) Hospital shares	Dec. 31, 2016 USD ($) Hospital shares	Oct. 31, 2018	Dec. 31, 2015 USD ($)
Summary Of Business And Significant Accounting Policies [Line Items]
Establishment of partial reserve in the allowance for doubtful accounts for self-pay balances outstanding from the date of discharge, in days													90 days
Establishment of fully reserve for self-pay balances outstanding from the date of discharge, in days													90 days
Establishment of fully reserve in the allowance for doubtful accounts for third party liability accounts from the date of discharge, in days													180 days
Patients treated at hospitals for non elective services gross income less than federal poverty guidelines													400.00%
Accounts receivable, net				$ 1,509,909,000				$ 1,500,898,000					$ 1,509,909,000	$ 1,500,898,000
Number of hospital facilities | Hospital													3
Capitalized interest													$ 2,300,000	1,000,000	$ 1,900,000
Depreciation expense													410,000,000	388,400,000	350,800,000
Impairment of goodwill or indefinite-lived intangible assets		$ 0												0	0
Impairment of other intangible assets													49,000,000	0	$ 0
Intangible assets net				173,000,000				220,000,000					$ 173,000,000	220,000,000
Number of inpatient facilities | Facility													4
Number of outpatient facilities | Facility													12
Amount of estimated future payments related to physician-related contractual commitments				$ 2,000,000				2,000,000					$ 2,000,000	$ 2,000,000
Amount of potential future financial obligations													$ 2,000,000
Behavioral health care facilities with outside owners holding non-controlling minority interest | Facility				2									2
Redeemable non-controlling interest balances				$ 4,000,000									$ 4,000,000
Non-controlling interest balances				77,000,000									$ 77,000,000
Anti-dilutive weighted average stock options excluded from computation of earnings per share | shares													7.9	6.2	2.2
Revenues				2,754,496,000	$ 2,648,913,000	$ 2,681,353,000	$ 2,687,516,000	2,642,787,000	$ 2,541,864,000	$ 2,612,356,000	$ 2,612,858,000		$ 10,772,278,000	$ 10,409,865,000	$ 9,766,210,000
Tradename
Summary Of Business And Significant Accounting Policies [Line Items]
Intangible assets net				75,000,000				124,000,000					75,000,000	$ 124,000,000			$ 124,000,000
Commercial Insurance Subsidiary
Summary Of Business And Significant Accounting Policies [Line Items]
Statutorily required capital reserves				112,000,000									$ 112,000,000
Universal Health Realty Income Trust
Summary Of Business And Significant Accounting Policies [Line Items]
Number of hospital facilities | Hospital													3	3	3
Investments				8,000,000									$ 8,000,000
Premier, Inc.
Summary Of Business And Significant Accounting Policies [Line Items]
Investments				56,000,000									56,000,000
Premier, Inc. | Group Purchasing Organization Agreement | Restricted Stock
Summary Of Business And Significant Accounting Policies [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													56,000,000	$ 33,000,000
Unrealized gain													23,000,000
Additional vested shares, value													$ 17,000,000
Building and Building Improvements | Minimum
Summary Of Business And Significant Accounting Policies [Line Items]
Property and equipment, useful lives, maximum years													20 years
Building and Building Improvements | Maximum
Summary Of Business And Significant Accounting Policies [Line Items]
Property and equipment, useful lives, maximum years													40 years
Equipment | Minimum
Summary Of Business And Significant Accounting Policies [Line Items]
Property and equipment, useful lives, maximum years													3 years
Equipment | Maximum
Summary Of Business And Significant Accounting Policies [Line Items]
Property and equipment, useful lives, maximum years													15 years
Acute Care Hospital Services
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues													$ 5,719,905,000	5,484,683,000	$ 5,112,950,000
Behavioral Health Services
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues	[1]												5,038,874,000	4,906,719,000	4,645,007,000
State Medicaid programs
Summary Of Business And Significant Accounting Policies [Line Items]
Revenue offset amount													179,000,000	171,000,000	166,000,000
Net aggregate benefit													208,000,000	186,000,000	161,000,000
Net revenues													64,000,000	55,000,000	$ 53,000,000
Illinois
Summary Of Business And Significant Accounting Policies [Line Items]
Accounts receivable, net				32,000,000				25,000,000					32,000,000	25,000,000
Accounts receivable net greater than sixty days Past due				$ 18,000,000				$ 8,000,000					$ 18,000,000	$ 8,000,000
Las Vegas, Nevada | Acute Care Hospital Services
Summary Of Business And Significant Accounting Policies [Line Items]
Number of hospital facilities | Hospital			6										6
Acquisition, cash paid			$ 445,000,000
Purchase price of minority ownership interests			418,000,000
Return of reserve capital to purchase of minority ownership interests			$ 27,000,000
Las Vegas, Nevada | Acute Care Hospital Services | Minimum
Summary Of Business And Significant Accounting Policies [Line Items]
Ownership interests purchased			26.10%
Las Vegas, Nevada | Acute Care Hospital Services | Maximum
Summary Of Business And Significant Accounting Policies [Line Items]
Ownership interests purchased			27.50%
Las Vegas, Nevada | Net Revenue | Geographic Concentration Risk
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of revenue													15.00%	15.00%	14.00%
Washington, District of Columbia | Acute Care Facilities | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners				20.00%									20.00%
Texas | Acute Care Facilities | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners				11.00%									11.00%
Pennsylvania | Behavioral Health Services | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners				20.00%									20.00%
Ohio | Behavioral Health Services | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners				30.00%									30.00%
Nevada | Acute Care Facilities | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners				5.00%									5.00%
Washington | Behavioral Health Services | Third-Party Ownership Interests
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of non-controlling, minority ownership interests held by outside owners																20.00%
Medicare
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues													$ 1,875,875,000	$ 1,816,840,000	$ 1,729,093,000
Medicare | Acute Care Hospital Services
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues													1,296,152,000	1,223,150,000	1,114,911,000
Medicare | Behavioral Health Services
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues													579,723,000	593,690,000	614,182,000
Health Care | State Medicaid programs
Summary Of Business And Significant Accounting Policies [Line Items]
Revenues													387,000,000	357,000,000	$ 327,000,000
ASU 2014-09
Summary Of Business And Significant Accounting Policies [Line Items]
Effect of change on after-tax net income													$ 1,000,000
ASU 2014-09 | Medicare
Summary Of Business And Significant Accounting Policies [Line Items]
Percentage of estimated net revenue adjustment													1.00%
ASU 2016-01 | Premier, Inc. | Other (Income) Expense, Net
Summary Of Business And Significant Accounting Policies [Line Items]
Unrealized gain													$ 6,000,000	$ 6,000,000

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $505 million in 2018, $429 million in 2017 and $241 million in 2016. Total assets at our U.K. behavioral health care facilities were approximately $1.224 billion as of December 31, 2018, $1.098 billion as of December 31, 2017 and $965 million as of December 31, 2016. In addition, included in our 2018 Behavioral Health Services operating segment Income (loss) before allocation of corporate overhead and income taxes is a pre-tax $49 million provision for asset impairment to reduce the carrying value of a tradename intangible asset.