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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Basic and Diluted:
Net Income (Loss)	$ 166,989	$ 182,814	$ 501,417	$ 500,789
Less: Net income attributable to unvested restricted share grants	(52)	(179)	(242)	(592)
Net income attributable to UHS - basic	166,937	182,635	501,175	500,197
Net income attributable to UHS - diluted	$ 166,937	$ 182,635	$ 501,175	$ 500,197
Weighted average number of common shares - basic	68,867	72,595	69,825	73,769
Net effect of dilutive stock options and grants based on the treasury stock method	757	465	825	743
Weighted average number of common shares and equivalents - diluted	69,624	73,060	70,650	74,512
Earnings per basic share attributable to UHS:	$ 2.42	$ 2.52	$ 7.18	$ 6.78
Earnings per diluted share attributable to UHS:	$ 2.40	$ 2.50	$ 7.09	$ 6.71