Revenue Recognition and Accounts Receivable Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Patient service revenues									$ 10,918,421	$ 10,709,981	$ 10,093,670
Other revenues									491,773	744,457	1,268,328
Total revenues	$ 2,898,584	$ 2,904,078	$ 2,842,705	$ 2,743,112	$ 2,821,124	$ 2,847,330	$ 2,886,953	$ 2,849,444	11,388,479	11,404,851	10,876,634
Revenue disaggregation table footnote
Provision for uncollectible accounts									21,715	49,587	485,364
Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(146,355)	(127,186)	(79,779)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues									6,129,697	6,063,891	5,253,012
Other revenues									264,538	492,812	902,289
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues									669,089	628,766	606,827
Other revenues									606	44,246	71,426
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									798,775	782,593	622,218
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									3,430,345	3,278,094	3,181,425
Other revenues									130,823	90,890	116,503
Other
Disaggregation of Revenue [Line Items]
Other revenues									110,961	150,745	202,713
U.S. dialysis
Disaggregation of Revenue [Line Items]
Total revenues									10,430,581	10,242,999	9,304,889
U.S. dialysis | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(132,325)	(92,950)	(55,176)
U.S. dialysis | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues									6,129,697	6,063,891	5,253,012
U.S. dialysis | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues									669,089	628,766	606,827
U.S. dialysis | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									446,010	446,999	362,567
U.S. dialysis | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									3,286,089	3,176,413	3,117,920
U.S. dialysis | Other
Disaggregation of Revenue [Line Items]
Other revenues									32,021	19,880	19,739
Other - Ancillary services
Disaggregation of Revenue [Line Items]
Total revenues									957,898	1,161,852	1,571,745
Other - Ancillary services | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues									(14,030)	(34,236)	(24,603)
Other - Ancillary services | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues									264,538	492,812	902,289
Other - Ancillary services | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues									606	44,246	71,426
Other - Ancillary services | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									352,765	335,594	259,651
Other - Ancillary services | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues									144,256	101,681	63,505
Other revenues									130,823	90,890	116,503
Other - Ancillary services | Other
Disaggregation of Revenue [Line Items]
Other revenues									$ 78,940	$ 130,865	$ 182,974