Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2017	Mar. 31, 2022
Commitments and Contingencies:
Corporate Integrity Agreement Period		5 years
Corporate Integrity Agreement Expiration Date		Oct. 22, 2019
Commitments to provide operating capital
Commitments and Contingencies:
Other potential commitments to provide operating capital to several dialysis centers		$ 13,027
US Attorney Prescription Drug Investigation
Commitments and Contingencies:
Litigation Settlement, Amount Awarded to Other Party	$ 63,700
Incremental Cash Portion | US Attorney Prescription Drug Investigation
Commitments and Contingencies:
Litigation Settlement, Amount Awarded to Other Party	41,500
Cash Paid For Portion Previously Refunded | US Attorney Prescription Drug Investigation
Commitments and Contingencies:
Litigation Settlement, Amount Awarded to Other Party	$ 22,200