Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Other revenues	$ 121,782	$ 118,889	$ 249,738	$ 232,312
Total revenues	2,879,979	2,842,705	5,721,216	5,585,817
Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(39,600)	(33,737)	(75,994)	(67,714)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,517,309	1,520,193	3,019,529	3,013,709
Other revenues	99,829	64,012	198,307	125,713
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	182,324	160,242	353,791	314,431
Other revenues	283	94	649	100
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	207,571	199,335	414,056	389,937
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	886,115	874,088	1,751,164	1,695,890
Other revenues	9,050	32,307	19,571	64,925
Other
Disaggregation of Revenue [Line Items]
Other revenues	17,098	26,171	40,143	48,826
U.S. dialysis
Disaggregation of Revenue [Line Items]
Total revenues	2,639,515	2,607,160	5,223,897	5,123,670
U.S. dialysis \| Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(35,429)	(30,334)	(67,670)	(60,975)
U.S. dialysis \| Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,517,309	1,520,193	3,019,529	3,013,709
U.S. dialysis \| Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	182,324	160,242	353,791	314,431
U.S. dialysis \| Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	116,758	110,565	228,669	216,692
U.S. dialysis \| Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	850,558	840,993	1,676,140	1,629,407
U.S. dialysis \| Other
Disaggregation of Revenue [Line Items]
Other revenues	7,995	5,501	13,438	10,406
Other—Ancillary services
Disaggregation of Revenue [Line Items]
Total revenues	240,464	235,545	497,319	462,147
Other—Ancillary services \| Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(4,171)	(3,403)	(8,324)	(6,739)
Other—Ancillary services \| Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues	99,829	64,012	198,307	125,713
Other—Ancillary services \| Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues	283	94	649	100
Other—Ancillary services \| Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	90,813	88,770	185,387	173,245
Other—Ancillary services \| Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	35,557	33,095	75,024	66,483
Other revenues	9,050	32,307	19,571	64,925
Other—Ancillary services \| Other
Disaggregation of Revenue [Line Items]
Other revenues	$ 9,103	$ 20,670	$ 26,705	$ 38,420