Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Patient service revenues	$ 2,781,169	$ 2,670,701	$ 8,150,386	$ 7,980,178
Other revenues	126,886	188,606	359,198	639,387
Total revenues	2,904,078	2,847,330	8,489,895	8,583,727
Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(35,845)	(33,785)	(103,559)	(91,691)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,558,890	1,513,191	4,572,599	4,524,449
Other revenues	65,759	130,746	191,472	427,532
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	176,292	159,165	490,723	466,948
Other revenues	227	12,042	327	43,991
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	207,931	193,958	597,866	580,548
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	866,229	817,834	2,562,120	2,436,338
Other revenues	33,503	20,205	98,428	77,633
Other
Disaggregation of Revenue [Line Items]
Other revenues	31,092	33,974	79,919	117,979
U.S. dialysis and related lab services
Disaggregation of Revenue [Line Items]
Total revenues	2,659,065	2,551,377	7,782,735	7,639,101
U.S. dialysis and related lab services | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(32,362)	(25,424)	(93,337)	(63,943)
U.S. dialysis and related lab services | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,558,890	1,513,191	4,572,599	4,524,449
U.S. dialysis and related lab services | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	176,292	159,165	490,723	466,948
U.S. dialysis and related lab services | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	116,984	113,043	333,675	330,500
U.S. dialysis and related lab services | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	828,953	786,470	2,458,360	2,366,182
U.S. dialysis and related lab services | Other
Disaggregation of Revenue [Line Items]
Other revenues	10,308	4,932	20,715	14,965
Other—Ancillary services and strategic initiatives
Disaggregation of Revenue [Line Items]
Total revenues	245,013	295,953	707,160	944,626
Other—Ancillary services and strategic initiatives | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(3,483)	(8,361)	(10,222)	(27,748)
Other—Ancillary services and strategic initiatives | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues	65,759	130,746	191,472	427,532
Other—Ancillary services and strategic initiatives | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Other revenues	227	12,042	327	43,991
Other—Ancillary services and strategic initiatives | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	90,947	80,915	264,191	250,048
Other—Ancillary services and strategic initiatives | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	37,276	31,364	103,760	70,156
Other revenues	33,503	20,205	98,428	77,633
Other—Ancillary services and strategic initiatives | Other
Disaggregation of Revenue [Line Items]
Other revenues	$ 20,784	$ 29,042	$ 59,204	$ 103,014