Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interest	Class A	Class B	Class C	Class D	Cumulative Dividends	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	UHS Common Stockholders' Equity	Noncontrolling Interest
Balance at Dec. 31, 2016	$ 4,597,594		$ 66	$ 893	$ 7	$ 0	$ (333,603)	$ 4,891,274	$ (25,417)	$ 4,533,220	$ 64,374
Balance at Dec. 31, 2016		$ 9,319
Common Stock
Issued/(converted) including tax benefits from exercise of stock options	10,379			9				10,370		10,379
Repurchased	(356,413)			(33)				(356,380)		(356,413)
Restricted share-based compensation expense	1,377							1,377		1,377
Dividends paid	(38,211)						(38,211)			(38,211)
Stock option expense	54,265							54,265		54,265
Distributions to noncontrolling interests	(22,932)	(1,781)									(22,932)
Other	635										635
Comprehensive income:
Net income to UHS / noncontrolling interests	772,148							752,303		752,303	19,845
Net income attributable to redeemable noncontrolling interest		(836)
Foreign currency translation adjustments	26,678								26,678	26,678
Unrealized loss on marketable security (net of income tax effect)	(1,360)								(1,360)	(1,360)
Unrealized derivative gains on cash flow hedges (net of income tax effect)	4,189								4,189	4,189
Minimum pension liability (net of income tax effect)	3,087								3,087	3,087
Subtotal - comprehensive income	804,742							752,303	32,594	784,897	19,845
Subtotal attributable to redeemable noncontrolling interest		(836)
Balance at Dec. 31, 2017	5,051,436		66	869	7		(371,814)	5,353,209	7,177	4,989,514	61,922
Balance at Dec. 31, 2017		6,702
Cumulative Effect on Retained Earnings, Net of Tax								(3,353)	3,353
Common Stock
Issued/(converted) including tax benefits from exercise of stock options	11,888			6				11,882		11,888
Repurchased	(414,002)			(34)				(413,968)		(414,002)
Restricted share-based compensation expense	2,924							2,924		2,924
Dividends paid	(37,342)						(37,342)			(37,342)
Stock option expense	61,061							61,061		61,061
Distributions to noncontrolling interests	(12,095)	(2,500)									(12,095)
Other	8,616										8,616
Comprehensive income:
Net income to UHS / noncontrolling interests	797,793							779,705		779,705	18,088
Net income attributable to redeemable noncontrolling interest		90
Reclassification due to the adoption of ASU No. 201802								1,802	(1,802)
Foreign currency translation adjustments	2,894								2,894	2,894
Unrealized derivative gains on cash flow hedges (net of income tax effect)	(2,138)								(2,138)	(2,138)
Minimum pension liability (net of income tax effect)	(5,242)								(5,242)	(5,242)
Subtotal - comprehensive income	793,307							778,154	(2,935)	775,219	18,088
Subtotal attributable to redeemable noncontrolling interest		90
Balance at Dec. 31, 2018	5,465,793		66	841	7		(409,156)	5,793,262	4,242	5,389,262	76,531
Balance at Dec. 31, 2018		4,292
Common Stock
Issued/(converted) including tax benefits from exercise of stock options	10,940			10				10,930		10,940
Repurchased	(753,927)			(57)				(753,870)		(753,927)
Restricted share-based compensation expense	8,222							8,222		8,222
Dividends paid	(53,003)						(53,003)			(53,003)
Stock option expense	60,106							60,106		60,106
Distributions to noncontrolling interests	(15,359)	(500)									(15,359)
Other	1,446										1,446
Comprehensive income:
Net income to UHS / noncontrolling interests	827,002							814,854		814,854	12,148
Net income attributable to redeemable noncontrolling interest		541
Foreign currency translation adjustments	24,193								24,193	24,193
Unrealized derivative gains on cash flow hedges (net of income tax effect)	(2,997)								(2,997)	(2,997)
Minimum pension liability (net of income tax effect)	6,455								6,455	6,455
Subtotal - comprehensive income	854,653							814,854	27,651	842,505	12,148
Subtotal attributable to redeemable noncontrolling interest		541
Balance at Dec. 31, 2019	5,578,871		$ 66	$ 794	$ 7	$ 0	$ (462,159)	$ 5,933,504	$ 31,893	$ 5,504,105	$ 74,766
Balance at Dec. 31, 2019	$ 4,000	$ 4,333