Acquisitions and Divestitures - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended					12 Months Ended									3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2010 Psychiatric Solutions Inc	Dec. 31, 2010 Psychiatric Solutions Inc	Jul. 31, 2011 Meadow Wood Behavioral Health System Bed	Dec. 31, 2011 Monte Vista Bed	Dec. 31, 2011 Red Rock Hospital Bed	Jan. 31, 2012 Hospital San Juan Capestrano Bed	Dec. 31, 2012 Auburn Regional Medical Center	Dec. 31, 2012 2012 Divestiture of Assets and Businesses	Dec. 31, 2012 2012 Divestiture of Assets and Businesses Peak Behavioral Health Services Bed	Dec. 31, 2011 2012 Divestiture of Assets and Businesses Peak Behavioral Health Services	Dec. 31, 2012 2012 Divestiture of Assets and Businesses Hospital San Juan Capestrano	Dec. 31, 2012 2012 Divestiture of Assets and Businesses Auburn Regional Medical Center Bed	Dec. 31, 2012 2012 Divestiture of Assets and Businesses Behavioral Health Care Facility Facility	Dec. 31, 2011 Two Thousand Eleven Divestiture of Assets and Businesses	Dec. 31, 2010 2010 Divestiture of Assets and Businesses	Dec. 31, 2012 2012 Acquisitions of Assets and Businesses	Dec. 31, 2012 2012 Acquisitions of Assets and Businesses	Dec. 31, 2011 2012 Acquisitions of Assets and Businesses	Dec. 31, 2012 2012 Acquisitions of Assets and Businesses Ascend Health Corporation	Dec. 31, 2012 2012 Acquisitions of Assets and Businesses Physician Practices and Various Real Property	Dec. 31, 2011 2011 Acquisitions of Assets and Businesses	Dec. 31, 2010 2010 Acquisitions of Assets and Businesses	Dec. 31, 2010 2010 Acquisitions of Assets and Businesses Psychiatric Solutions Inc	Nov. 15, 2010 2010 Acquisitions of Assets and Businesses Psychiatric Solutions Inc
Business Acquisition [Line Items]
Acquisition, cash paid																			$ 528,000,000	$ 528,000,000		$ 503,000,000	$ 25,000,000	$ 29,000,000	$ 1,958,000,000	$ 1,958,000,000	$ 1,960,000,000
Pro forma net revenues					7,300,000,000															7,110,000,000	6,900,000,000
Pro forma net income attributable to UHS					342,000,000															464,000,000	401,000,000
Pro forma net income attributable to UHS per diluted share					$ 3.47															$ 4.74	$ 4.06
Transaction costs incurred																					5,000,000
Transaction costs incurred, per diluted share																					$ 0.06
Net revenues				227,000,000								18,000,000	14,000,000						42,000,000
Net cash proceeds from divestiture of assets and businesses											149,000,000			50,000,000	93,000,000	6,000,000	68,000,000	21,000,000
Number of acute care hospital beds included in acquisition															159
Number of non-operating behavioral health facilities																2
Number of beds												104
Number of beds included in divestiture						58	101	21	108
Aggregate pre-tax net gain on the divestiture	26,419,000	442,000	0							26,000,000
Debt assumed on the acquisition of businesses and real property																								17,000,000	1,082,000,000	1,082,000,000	1,080,000,000
Acquisition, total purchase price																											$ 3,040,000,000
Previously held minority ownership interest, percentage																										20.00%