Computation of Basic and Diluted Earnings Per Share for classes A, B, C and D Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic and Diluted:
Net income attributable to UHS	$ 185,394	$ 185,577	$ 391,449	$ 376,336
Less: Net income attributable to unvested restricted share grants	(82)	(84)	(176)	(173)
Net income attributable to UHS – basic and diluted	$ 185,312	$ 185,493	$ 391,273	$ 376,163
Weighted average number of common shares - basic	96,247	97,109	96,416	97,358
Net effect of dilutive stock options and grants based on the treasury stock method	795	1,280	791	1,284
Weighted average number of common shares and equivalents - diluted	97,042	98,389	97,207	98,642
Earnings per basic share attributable to UHS:	$ 1.93	$ 1.91	$ 4.06	$ 3.86
Earnings per diluted share attributable to UHS:	$ 1.91	$ 1.89	$ 4.03	$ 3.81