Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Basic and diluted:
Net Income	$ 178,738	$ 157,265	$ 195,449	$ 215,719	$ 191,317	$ 163,654	$ 201,404	$ 194,323	$ 747,171	$ 750,698	$ 604,996
Less: Net income attributable to noncontrolling interest	$ (4,530)	$ (5,400)	$ (9,872)	$ (24,960)	$ (17,568)	$ (13,367)	$ (19,211)	$ (20,024)	(44,762)	(70,170)	(59,653)
Less: Net income attributable to unvested restricted share grants									(314)	(281)	(236)
Net income attributable to UHS—basic and diluted									$ 702,095	$ 680,247	$ 545,107
Weighted average number of common shares—basic									97,208	98,797	98,826
Total basic earnings per share	$ 1.80	$ 1.56	$ 1.91	$ 1.95	$ 1.76	$ 1.52	$ 1.84	$ 1.76	$ 7.22	$ 6.89	$ 5.52
Weighted average number of common shares									97,208	98,797	98,826
Net effect of dilutive stock options and grants based on the treasury stock method									1,172	1,897	1,718
Weighted average number of common shares and equivalents—diluted									98,380	100,694	100,544
Total diluted earnings per share	$ 1.78	$ 1.54	$ 1.89	$ 1.93	$ 1.74	$ 1.48	$ 1.80	$ 1.73	$ 7.14	$ 6.76	$ 5.42