Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Other revenues	$ 109,684	$ 116,658	$ 222,349	$ 217,932
Total revenues	3,000,369	2,926,757	5,873,068	5,744,312
Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(21,769)	(19,389)	(45,184)	(41,558)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	1,539,639	1,529,534	3,022,405	2,993,621
Other revenues	87,236	93,262	180,475	176,859
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	216,014	186,873	421,790	376,528
Other revenues	396	232	965	769
Other Government Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	218,489	202,732	422,120	400,427
Commercial Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	936,904	910,370	1,826,814	1,797,372
Other revenues	3,619	8,207	4,825	9,546
Other
Disaggregation of Revenue [Line Items]
Other revenues	19,841	14,936	38,858	30,748
U.S. dialysis
Disaggregation of Revenue [Line Items]
Total revenues	2,710,254	2,643,851	5,300,365	5,196,778
U.S. dialysis \| Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(20,361)	(19,389)	(42,410)	(41,558)
U.S. dialysis \| Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	1,539,639	1,529,534	3,022,405	2,993,621
U.S. dialysis \| Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	216,014	186,873	421,790	376,528
U.S. dialysis \| Other Government Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	92,525	86,079	174,570	166,879
U.S. dialysis \| Commercial Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	876,033	854,662	1,711,427	1,689,240
U.S. dialysis \| Other
Disaggregation of Revenue [Line Items]
Other revenues	6,404	6,092	12,583	12,068
Other—Ancillary services
Disaggregation of Revenue [Line Items]
Total revenues	290,115	282,906	572,703	547,534
Other—Ancillary services \| Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total revenues	(1,408)		(2,774)
Other—Ancillary services \| Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues	87,236	93,262	180,475	176,859
Other—Ancillary services \| Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues	396	232	965	769
Other—Ancillary services \| Other Government Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	125,964	116,653	247,550	233,548
Other—Ancillary services \| Commercial Payors
Disaggregation of Revenue [Line Items]
Dialysis patient service revenues	60,871	55,708	115,387	108,132
Other revenues	3,619	8,207	4,825	9,546
Other—Ancillary services \| Other
Disaggregation of Revenue [Line Items]
Other revenues	$ 13,437	$ 8,844	$ 26,275	$ 18,680