Acquisitions and Divestitures - Additional Information (Detail)	3 Months Ended												12 Months Ended
	Dec. 31, 2016 USD ($) Facility	Sep. 30, 2016 USD ($) Bed	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Facility Bed	Sep. 30, 2015 USD ($) Hospital Bed	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) Bed	Dec. 31, 2014 Bed	Sep. 30, 2014 Hospital Facility Bed	Jun. 30, 2014 Bed	Mar. 31, 2014 Bed	Dec. 31, 2016 USD ($) Hospital $ / shares	Dec. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) Bed $ / shares	Dec. 28, 2016 USD ($)
Business Acquisition [Line Items]
Goodwill recognition description													Goodwill of the facilities acquired during each of the last 3 years is computed, pursuant to the residual method, by deducting the fair value of the acquired assets and liabilities from the total purchase price. The factors that contribute to the recognition of goodwill, which may also influence the purchase price, include the following for each of the acquired facilities: (i) the historical cash flows and income levels; (ii) the reputations in their respective markets; (iii) the nature of the respective operations, and; (iv) the future cash flows and income growth projections.
Net revenues	$ 2,475,685,000	$ 2,409,872,000	$ 2,430,855,000	$ 2,449,798,000	$ 2,315,239,000	$ 2,227,655,000	$ 2,275,204,000	$ 2,225,353,000					$ 9,766,210,000	$ 9,043,451,000	$ 8,205,088,000
Aggregate cash proceeds from divestiture of businesses													$ 0	3,000,000	15,000,000
Number of hospital facilities | Hospital													3
2016 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid													$ 614,000,000
Unaudited pro forma net revenues													9,980,000,000	9,280,000,000
Unaudited pro forma net income attributable to UHS													$ 730,000,000	$ 708,000,000
Unaudited pro forma net income attributable to UHS per diluted share | $ / shares													$ 7.25	$ 7.03
Cambian Adult Services
Business Acquisition [Line Items]
Number of facilities | Facility	79
Number of outpatient centers | Facility	2
Total purchase price of acquisition																$ 473,000,000
Cambian Adult Services | Maximum
Business Acquisition [Line Items]
Business combination term for finalize purchase price allocations from the date of acquisition													1 year
Desert View Hospital
Business Acquisition [Line Items]
Number of beds | Bed		25
Net revenues													$ 12,000,000
2015 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid														$ 534,000,000
Net revenues														30,000,000
Unaudited pro forma net revenues														9,170,000,000	8,350,000,000
Unaudited pro forma net income attributable to UHS														$ 690,000,000	$ 545,000,000
Unaudited pro forma net income attributable to UHS per diluted share | $ / shares														$ 6.85	$ 5.42
Behavioral Health Services
Business Acquisition [Line Items]
Number of beds | Bed								46
Alpha Hospitals Holdings Limited
Business Acquisition [Line Items]
Number of beds | Bed						305
Number of hospital facilities | Hospital						4
Foundations Recovery Network, LLC
Business Acquisition [Line Items]
Number of facilities | Facility					4
Number of outpatient centers | Facility					8
Number of beds | Bed					322
Indefinite lived Tradenames					$ 124,000,000									$ 124,000,000
2014 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid															$ 431,000,000
Unaudited pro forma net revenues															8,280,000,000
Unaudited pro forma net income attributable to UHS															$ 558,000,000
Unaudited pro forma net income attributable to UHS per diluted share | $ / shares															$ 5.55
Cygnet Health Care Limited
Business Acquisition [Line Items]
Number of facilities | Facility										17
Number of beds | Bed										723					124
Net revenues															$ 175,000,000
Number of hospital facilities | Hospital										15
Number of nursing homes | Hospital										2
Acquired Company Two
Business Acquisition [Line Items]
Number of beds | Bed											124
Palo Verde Behavioral Health
Business Acquisition [Line Items]
Number of beds | Bed												48
The Bridgeway
Business Acquisition [Line Items]
Number of beds | Bed									103
Cygnet Hospital-Harrow
Business Acquisition [Line Items]
Number of beds | Bed									44