Quarterly Results (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 3,086,935	$ 2,912,541	$ 2,729,754	$ 2,829,667	$ 2,896,247	$ 2,822,453	$ 2,855,168	$ 2,804,391	$ 11,558,897	$ 11,378,259	$ 10,772,278
Net income	307,734	244,092	256,504	144,460	248,010	100,870	241,265	237,398	952,790	827,543	797,883
Less: Net income attributable to noncontrolling interests	(974)	2,813	4,575	2,423	2,834	3,680	2,945	3,230	8,837	12,689	18,178
Net income attributable to UHS	$ 308,708	$ 241,279	$ 251,929	$ 142,037	$ 245,176	$ 97,190	$ 238,320	$ 234,168	$ 943,953	$ 814,854	$ 779,705
Earnings per share attributable to UHS-Basic:
Total basic earnings per share	$ 3.63	$ 2.84	$ 2.97	$ 1.64	$ 2.81	$ 1.10	$ 2.67	$ 2.57	$ 11.06	$ 9.16	$ 8.35
Earnings per share attributable to UHS-Diluted:
Total diluted earnings per share	$ 3.60	$ 2.82	$ 2.95	$ 1.64	$ 2.79	$ 1.10	$ 2.66	$ 2.57	$ 10.99	$ 9.13	$ 8.31