Goodwill - Changes in Goodwill by Reportable Segments (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Beginning balance	$ 7,046,241	$ 6,919,109
Acquisitions	34,769	173,244
Divestitures	(3,213)	(1,745)
Foreign currency and other adjustments	(55,155)	(44,367)
Ending balance	7,022,642	7,046,241
Goodwill, before accumulated impairment charges	7,131,972
Accumulated impairment charges	(109,330)
Ending balance	7,022,642	7,046,241
U.S. dialysis
Goodwill [Roll Forward]
Beginning balance	6,400,162	6,309,928
Acquisitions	16,750	91,979
Divestitures	(87)	(1,745)
Foreign currency and other adjustments	0	0
Ending balance	6,416,825	6,400,162
Goodwill, before accumulated impairment charges	6,416,825
Accumulated impairment charges	0
Ending balance	6,416,825	6,400,162
Other—Ancillary services
Goodwill [Roll Forward]
Beginning balance	646,079	609,181
Acquisitions	18,019	81,265
Divestitures	(3,126)	0
Foreign currency and other adjustments	(55,155)	(44,367)
Ending balance	605,817	646,079
Goodwill, before accumulated impairment charges	715,147
Accumulated impairment charges	(109,330)
Ending balance	$ 605,817	$ 646,079