Goodwill - Changes in Goodwill by Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Beginning balance	$ 7,076,610	$ 7,046,241
Acquisitions		49,047
Divestitures		(3,350)
Foreign currency and other adjustments	13,701	(15,328)
Ending balance	7,090,311	7,076,610
Goodwill, before accumulated impairment charges	7,211,216
Accumulated impairment charges	(120,905)
Ending balance	7,090,311	7,076,610
U.S. dialysis
Goodwill [Roll Forward]
Beginning balance	6,416,825	6,400,162
Acquisitions		16,750
Divestitures		(87)
Foreign currency and other adjustments	0	0
Ending balance	6,416,825	6,416,825
Goodwill, before accumulated impairment charges	6,416,825
Accumulated impairment charges	0
Ending balance	6,416,825	6,416,825
Other—Ancillary services
Goodwill [Roll Forward]
Beginning balance	659,785	646,079
Acquisitions		32,297
Divestitures		(3,263)
Foreign currency and other adjustments	13,701	(15,328)
Ending balance	673,486	659,785
Goodwill, before accumulated impairment charges	794,391
Accumulated impairment charges	(120,905)
Ending balance	$ 673,486	$ 659,785