Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Patient service revenues	$ 2,670,701	$ 2,561,543	$ 7,980,178	$ 7,478,938
Other revenues	188,606	322,849	639,387	952,762
Total revenues	2,847,330	2,765,071	8,583,727	8,095,721
Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(33,785)	(19,471)	(91,691)	(57,047)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,513,191	1,338,155	4,524,449	3,924,255
Other revenues	130,746	232,251	427,532	682,964
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	159,165	155,113	466,948	450,984
Other revenues	12,042	17,142	43,991	54,757
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	193,958	161,924	580,548	454,997
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	817,834	800,505	2,436,338	2,351,282
Other revenues	20,205	27,222	77,633	79,241
Other
Disaggregation of Revenue [Line Items]
Other revenues	33,974	52,230	117,979	154,288
U.S. dialysis and related lab services
Disaggregation of Revenue [Line Items]
Total revenues	2,551,377	2,356,999	7,639,101	6,928,323
U.S. dialysis and related lab services | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(25,424)	(13,475)	(63,943)	(38,559)
U.S. dialysis and related lab services | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,513,191	1,338,155	4,524,449	3,924,255
U.S. dialysis and related lab services | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	159,165	155,113	466,948	450,984
U.S. dialysis and related lab services | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	113,043	89,243	330,500	271,947
U.S. dialysis and related lab services | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	786,470	783,171	2,366,182	2,304,745
U.S. dialysis and related lab services | Other
Disaggregation of Revenue [Line Items]
Other revenues	4,932	4,792	14,965	14,951
Other—Ancillary services and strategic initiatives
Disaggregation of Revenue [Line Items]
Total revenues	295,953	408,072	944,626	1,167,398
Other—Ancillary services and strategic initiatives | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(8,361)	(5,996)	(27,748)	(18,488)
Other—Ancillary services and strategic initiatives | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues	130,746	232,251	427,532	682,964
Other—Ancillary services and strategic initiatives | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues	12,042	17,142	43,991	54,757
Other—Ancillary services and strategic initiatives | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	80,915	72,681	250,048	183,050
Other—Ancillary services and strategic initiatives | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	31,364	17,334	70,156	46,537
Other revenues	20,205	27,222	77,633	79,241
Other—Ancillary services and strategic initiatives | Other
Disaggregation of Revenue [Line Items]
Other revenues	$ 29,042	$ 47,438	$ 103,014	$ 139,337