Noncontrolling Interests Subject to Put Provisions and Other Commitments - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Other Commitments [Line Items]
Schedule of Joint ventures to dissolve	Certain consolidated joint ventures are contractually scheduled to dissolve after terms ranging from ten to fifty years.
Minimum
Other Commitments [Line Items]
Scheduled dissolution term of joint ventures	10 years
Maximum
Other Commitments [Line Items]
Scheduled dissolution term of joint ventures	50 years
Commitments to provide operating capital
Other Commitments [Line Items]
Other potential commitments to provide operating capital to several dialysis centers	$ 1,000