Revenue Recognition and Accounts Receivable Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ 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
Disaggregation of Revenue [Line Items]
Patient service revenues									$ 11,039,709	$ 10,918,421	$ 10,709,981
Other revenues									524,353	491,773	744,457
Total revenues	$ 2,905,322	$ 2,924,066	$ 2,879,979	$ 2,841,237	$ 2,898,584	$ 2,904,078	$ 2,842,705	$ 2,743,112	11,550,604	11,388,479	11,404,851
Revenue disaggregation table footnote
Provision for uncollectible accounts									13,458	21,715	49,587
Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(162,029)	(146,355)	(127,186)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues									6,048,043	6,129,697	6,063,891
Other revenues									419,662	264,538	492,812
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues									744,862	669,089	628,766
Other revenues									1,227	606	44,246
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									836,481	798,775	782,593
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									3,540,956	3,430,345	3,278,094
Other revenues									33,246	130,823	90,890
Other
Disaggregation of Revenue [Line Items]
Other revenues									88,156	110,961	150,745
U.S. dialysis
Disaggregation of Revenue [Line Items]
Total revenues									10,514,649	10,430,581	10,242,999
U.S. dialysis | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(145,286)	(132,325)	(92,950)
U.S. dialysis | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues									6,048,043	6,129,697	6,063,891
U.S. dialysis | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues									744,862	669,089	628,766
U.S. dialysis | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									455,897	446,010	446,999
U.S. dialysis | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									3,370,562	3,286,089	3,176,413
U.S. dialysis | Other
Disaggregation of Revenue [Line Items]
Other revenues									40,571	32,021	19,880
Other - Ancillary services
Disaggregation of Revenue [Line Items]
Total revenues									1,035,955	957,898	1,161,852
Other - Ancillary services | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(16,743)	(14,030)	(34,236)
Other - Ancillary services | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues									419,662	264,538	492,812
Other - Ancillary services | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues									1,227	606	44,246
Other - Ancillary services | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									380,584	352,765	335,594
Other - Ancillary services | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									170,394	144,256	101,681
Other revenues									33,246	130,823	90,890
Other - Ancillary services | Other
Disaggregation of Revenue [Line Items]
Other revenues									$ 47,585	$ 78,940	$ 130,865