XML 64 R39.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Schedule of Changes in Contractual Allowance (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]      
Balance, beginning of year $ 15,433 $ 9,205 $ 6,345
Add: allowance for contractual adjustments 20,916 15,518 9,095
Less: contractual adjustments (15,068) (9,290) (6,235)
Balance, end of year $ 21,281 $ 15,433 $ 9,205