Nature of Operations, Proposed Merger, Basis of Presentation and Principles of Consolidation (Details) $ / shares in Units, $ in Millions	Oct. 27, 2017 USD ($)	Oct. 18, 2017	Mar. 31, 2018 country	Aug. 07, 2017 $ / shares
Accounting Policies [Abstract]
Number of countries in which entity operates | country			21
Fresenius Medical Care Holdings, Inc.
Business Acquisition [Line Items]
Share price (in dollars per share) | $ / shares				$ 30.00
Business combination, waiting period, extension term		30 days
Termination of merger agreement, extension term	180 days
Termination of merger agreement, fee paid to acquiree	$ 100
Termination of merger agreement, fee paid to acquirer	$ 60
Termination of merger agreement, period to publicly withdraw from the agreement before termination	10 days
Termination of merger agreement, period to not enter into alternative acquisition after termination	12 months