Revenue Recognition and Accounts Receivable - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable	$ 1,824,282	$ 1,795,598
Medicare bad debt claims
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable	$ 1,101,837	$ 1,038,248
Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts Receivable Period Outstanding	1 year
Patient Services Customer Concentration Risk | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Number of concentration risk customers	0	0
Concentration risk percentage	10.00%	10.00%
Accounts receivable	$ 0
Percentage Of Accounts Receivable Six Months Or More Past Due	17.00%	18.00%
Accounts Receivable Period Outstanding	6 months	6 months
Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 0	$ 37,274
Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, allowance	$ 0	$ 8,328