Acquisitions and Divestitures - Additional Information (Detail) (USD $)	12 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended				12 Months Ended
	Dec. 31, 2014 Facility	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Dec. 31, 2012	Nov. 30, 2010 Facility	Sep. 30, 2014 Bed Hospital Facility	Jun. 30, 2014 Bed	Mar. 31, 2014 Bed	Dec. 31, 2014 Bed	Feb. 28, 2015 Bed
Business Acquisition [Line Items]
Number of hospitals	3
Aggregate cash proceeds from divestiture of businesses	$ 15,000,000
Aggregate pre-tax net gain on the divestiture		3,080,000	26,419,000
Auburn Regional Medical Center
Business Acquisition [Line Items]
Aggregate pre-tax net gain on the divestiture			26,000,000
2012 Divestiture of Assets and Businesses
Business Acquisition [Line Items]
Net cash proceeds from divestiture of assets and businesses			149,000,000
2012 Divestiture of Assets and Businesses | Peak Behavioral Health Services
Business Acquisition [Line Items]
Number of beds			104		104
2012 Divestiture of Assets and Businesses | Hospital San Juan Capestrano
Business Acquisition [Line Items]
Net cash proceeds from divestiture of assets and businesses			50,000,000
Number of acute care hospital beds included in acquisition			108
2012 Divestiture of Assets and Businesses | Auburn Regional Medical Center
Business Acquisition [Line Items]
Net cash proceeds from divestiture of assets and businesses			93,000,000
Number of acute care hospital beds included in acquisition			159
2012 Divestiture of Assets and Businesses | Behavioral Health Care Facility
Business Acquisition [Line Items]
Net cash proceeds from divestiture of assets and businesses			6,000,000
Number of non-operating behavioral health facilities			2		2
Two Thousand Thirteen Divestiture of Assets and Businesses | Peak Behavioral Health Services
Business Acquisition [Line Items]
Net cash proceeds from divestiture of assets and businesses		37,000,000		24,000,000
Aggregate pre-tax net gain on the divestiture		3,000,000		3,000,000
2013 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid		13,000,000
Pro forma net revenues		7,620,000,000
Pro forma net income attributable to UHS		522,000,000
Pro forma net income attributable to UHS per diluted share		$ 5.25
2012 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid			528,000,000
Net revenues					42,000,000
Pro forma net revenues			7,110,000,000
Pro forma net income attributable to UHS			464,000,000
Pro forma net income attributable to UHS per diluted share			$ 4.74
2012 Acquisitions of Assets and Businesses | Ascend Health Corporation
Business Acquisition [Line Items]
Acquisition, cash paid			503,000,000
2012 Acquisitions of Assets and Businesses | Physician Practices and Various Real Property
Business Acquisition [Line Items]
Acquisition, cash paid			25,000,000
2014 Acquisitions of Assets and Businesses
Business Acquisition [Line Items]
Acquisition, cash paid	431,000,000
Pro forma net revenues	8,280,000,000
Pro forma net income attributable to UHS	558,000,000
Pro forma net income attributable to UHS per diluted share	$ 5.55
Cygnet Health Care Limited
Business Acquisition [Line Items]
Number of beds							723
Number of facilities						18	17
Number of hospitals							15
Number of nursing homes						2	2
Net revenues	$ 175,000,000
Psychiatric Institute
Business Acquisition [Line Items]
Number of beds								124
Palo Verde Behavioral Health
Business Acquisition [Line Items]
Number of beds									48
The Bridgeway
Business Acquisition [Line Items]
Number of beds										103
Cygnet Hospital-Harrow
Business Acquisition [Line Items]
Number of beds										44
Cygnet Hospital-Taunton | Scenario, Forecast
Business Acquisition [Line Items]
Number of beds											46