Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic and Diluted:
Net income attributable to UHS	$ 234,168	$ 223,832
Less: Net income attributable to unvested restricted share grants	(515)	(104)
Net income attributable to UHS – basic and diluted	$ 233,653	$ 223,728
Weighted average number of common shares - basic	90,776	94,226
Net effect of dilutive stock options and grants based on the treasury stock method	191	457
Weighted average number of common shares and equivalents - diluted	90,967	94,683
Earnings per basic share attributable to UHS:	$ 2.57	$ 2.37
Earnings per diluted share attributable to UHS:	$ 2.57	$ 2.36