Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic and Diluted:
Net income attributable to UHS	$ 241,279	$ 97,190	$ 635,245	$ 569,678
Less: Net income attributable to unvested restricted share grants	(790)	(243)	(1,987)	(1,414)
Net income attributable to UHS – basic and diluted	$ 240,489	$ 96,947	$ 633,258	$ 568,264
Weighted average number of common shares - basic	84,672	87,952	85,172	89,288
Net effect of dilutive stock options and grants based on the treasury stock method	575	403	415	231
Weighted average number of common shares and equivalents - diluted	85,247	88,355	85,587	89,519
Earnings per basic share attributable to UHS:	$ 2.84	$ 1.10	$ 7.44	$ 6.36
Earnings per diluted share attributable to UHS:	$ 2.82	$ 1.10	$ 7.40	$ 6.35