v2.4.0.8
Concentrations - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Accounts Receivable | Government-based Programs, Medicare and Medicaid
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 80.00%    
Dialysis And Related Lab Services | Sales Revenue, Services, Net | Supplier Concentration Risk
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 3.00% 3.00%  
Dialysis And Related Lab Services | Sales Revenue, Services, Net | Government-based Programs, Medicare and Medicaid
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 66.00% 66.00% 66.00%
Accounts receivable, and other receivables, from Medicare and Medicaid-assigned plans $ 679,006 $ 629,178  
HealthCare Partners (HCP)
     
Concentration Risk [Line Items]      
Number of health plans 3    
HealthCare Partners (HCP) | Sales Revenue, Services, Net | Government-based Programs, Medicare and Medicaid
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 69.00%    
HealthCare Partners (HCP) | Sales Revenue, Services, Net | Product Concentration Risk
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 67.00%    
HealthCare Partners (HCP) | Accounts Receivable
     
Concentration Risk [Line Items]      
Concentration Risk, Percentage 69.00%