Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 228,669	$ 210,527
Other comprehensive income (loss):
Unrealized derivative gains on cash flow hedges	2,124	3,066
Foreign currency translation adjustment	(4,341)	7,236
Other	2,367	1,094
Other comprehensive income before tax	150	11,396
Income tax expense related to items of other comprehensive income	1,077	1,551
Total other comprehensive income (loss), net of tax	(927)	9,845
Comprehensive income	227,742	220,372
Less: Comprehensive income attributable to noncontrolling interests	4,837	4,472
Comprehensive income attributable to UHS	$ 222,905	$ 215,900