Noncontrolling Interests Subject to Put Provisions and Other Commitments - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
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	$ 3,441