Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Basic and Diluted:
Net income attributable to UHS	$ 209,091	$ 142,037
Less: Net income attributable to unvested restricted share grants	(552)	(373)
Net income attributable to UHS – basic and diluted	$ 208,539	$ 141,664
Weighted average number of common shares - basic	84,782	86,212
Net effect of dilutive stock options and grants based on the treasury stock method	1,014	243
Weighted average number of common shares and equivalents - diluted	85,796	86,455
Earnings per basic share attributable to UHS:	$ 2.46	$ 1.64
Earnings per diluted share attributable to UHS:	$ 2.43	$ 1.64