Revenue Recognition Segment Revenue by Payor (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Patient service revenues	$ 2,734,065	$ 2,718,403	$ 5,369,217	$ 5,309,477
Other revenues	118,889	217,956	232,312	450,781
Total revenues	2,842,705	2,886,953	5,585,817	5,736,397
Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(33,737)	(29,285)	(67,714)	(57,906)
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,520,193	1,526,066	3,013,709	3,011,258
Other revenues	64,012	154,028	125,713	296,786
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	160,242	150,288	314,431	307,783
Other revenues	94	16,158	100	31,949
Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	199,335	196,868	389,937	386,526
Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	874,088	815,871	1,695,890	1,618,568
Other revenues	32,307	17,006	64,925	57,427
Other
Disaggregation of Revenue [Line Items]
Other revenues	26,171	39,953	48,826	84,006
U.S. dialysis and related lab services
Disaggregation of Revenue [Line Items]
Total revenues	2,607,160	2,568,247	5,123,670	5,087,724
U.S. dialysis and related lab services | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(30,334)	(20,096)	(60,975)	(38,519)
U.S. dialysis and related lab services | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient service revenues	1,520,193	1,526,066	3,013,709	3,011,258
Other revenues
U.S. dialysis and related lab services | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues	160,242	150,288	314,431	307,783
Other revenues
U.S. dialysis and related lab services | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	110,565	110,338	216,692	217,458
U.S. dialysis and related lab services | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	840,993	796,732	1,629,407	1,579,711
Other revenues
U.S. dialysis and related lab services | Other
Disaggregation of Revenue [Line Items]
Other revenues	5,501	4,919	10,406	10,033
Other—Ancillary services and strategic initiatives
Disaggregation of Revenue [Line Items]
Total revenues	235,545	318,706	462,147	648,673
Other—Ancillary services and strategic initiatives | Intersegment Elimination
Disaggregation of Revenue [Line Items]
Total revenues	(3,403)	(9,189)	(6,739)	(19,387)
Other—Ancillary services and strategic initiatives | Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Other revenues	64,012	154,028	125,713	296,786
Other—Ancillary services and strategic initiatives | Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient service revenues
Other revenues	94	16,158	100	31,949
Other—Ancillary services and strategic initiatives | Other Government Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	88,770	86,530	173,245	169,068
Other—Ancillary services and strategic initiatives | Commercial Payors
Disaggregation of Revenue [Line Items]
Patient service revenues	33,095	19,139	66,483	38,857
Other revenues	32,307	17,006	64,925	57,427
Other—Ancillary services and strategic initiatives | Other
Disaggregation of Revenue [Line Items]
Other revenues	$ 20,670	$ 35,034	$ 38,420	$ 73,973