Computation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic and diluted:
Net Income									$ 489,047	$ 448,870	$ 275,795
Less: Net income attributable to noncontrolling interest									(45,601)	(50,703)	(45,612)
Less: Net income attributable to unvested restricted share grants									(497)	(521)	(918)
Net income attributable to UHS-basic and diluted									$ 442,949	$ 397,646	$ 229,265
Weighted average number of common shares-basic									96,821	97,199	96,786
Total basic earnings per share	$ 1.39	$ 0.74	$ 1.11	$ 1.33	$ 0.99	$ 0.87	$ 1.06	$ 1.17	$ 4.57	$ 4.09	$ 2.37
Weighted average number of common shares-basic									96,821	97,199	96,786
Net effect of dilutive stock options and grants based on the treasury stock method									890	1,338	1,187
Weighted average number of common shares and equivalents-diluted									97,711	98,537	97,973
Total diluted earnings per share	$ 1.39	$ 0.73	$ 1.10	$ 1.31	$ 0.98	$ 0.86	$ 1.04	$ 1.15	$ 4.53	$ 4.04	$ 2.34