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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic and diluted:
Net Income									$ 750,698	$ 604,996	$ 554,023
Less: Net income attributable to noncontrolling interest									(70,170)	(59,653)	(43,290)
Less: Net income attributable to unvested restricted share grants									(281)	(236)	(294)
Net income attributable to UHS—basic and diluted									$ 680,247	$ 545,107	$ 510,439
Weighted average number of common shares—basic									98,797	98,826	98,033
Total basic earnings per share	$ 1.76	$ 1.52	$ 1.84	$ 1.76	$ 1.75	$ 0.84	$ 1.53	$ 1.40	$ 6.89	$ 5.52	$ 5.21
Weighted average number of common shares									98,797	98,826	98,033
Net effect of dilutive stock options and grants based on the treasury stock method									1,897	1,718	1,328
Weighted average number of common shares and equivalents—diluted									100,694	100,544	99,361
Total diluted earnings per share	$ 1.74	$ 1.48	$ 1.80	$ 1.73	$ 1.71	$ 0.82	$ 1.51	$ 1.38	$ 6.76	$ 5.42	$ 5.14