Quarterly report pursuant to Section 13 or 15(d)

Nature of Business and Basis of Consolidation and Presentation (Details)

v3.21.2
Nature of Business and Basis of Consolidation and Presentation (Details)
$ / shares in Units, $ in Millions
Nov. 01, 2021
USD ($)
$ / shares
shares
Oct. 12, 2021
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
province
center
state
$ / shares
shares
Jan. 11, 2021
$ / shares
shares
Jan. 10, 2021
shares
Dec. 31, 2020
$ / shares
shares
Organization, Consolidation and Presentation of Financial Statements [Abstract]            
Number of centers | center     155      
Number of states in which entity operates | state     29      
Number of provinces in which entity operates | province     1      
Sale of Stock [Line Items]            
Common stock, authorized (in shares)     200,000,000 200,000,000 170,000,000 170,000,000
Common stock, par value (in usd per share) | $ / shares     $ 0.01 $ 0.01   $ 0.01
Preferred stock, authorized (in shares)       25,000,000    
Preferred stock, par value (in usd per share) | $ / shares       $ 0.01    
Unrecognized share-based compensation expense | $     $ 362.5      
Subsequent Event            
Sale of Stock [Line Items]            
Stock issued upon conversion (in shares)   6,700,000        
Conversion of mezzanine equity, shares issued (in shares)   600,000        
Common stock, authorized (in shares)   500,000,000        
Common stock, par value (in usd per share) | $ / shares   $ 0.01        
Preferred stock, authorized (in shares)   10,000,000        
Preferred stock, par value (in usd per share) | $ / shares   $ 0.01        
Subsequent Event | Term Loan Facility, maturing December 2024 | Term Loan Facility            
Sale of Stock [Line Items]            
Repayments of debt | $   $ 575.7        
Prepayment penalty | $   $ 5.7        
Subsequent Event | Series A Preferred Stock            
Sale of Stock [Line Items]            
Number of shares converted (in shares)   5,400,000        
Conversion of mezzanine equity, shares converted (in shares)   500,000        
IPO | Subsequent Event            
Sale of Stock [Line Items]            
Sale of common stock (in shares) 39,000,000          
Sale of common stock, price (in usd per share) | $ / shares   $ 18.00        
Sale of common stock, gross proceeds | $ $ 702.0          
Underwriting discounts and other offering expenses | $ 22.9          
Sale of common stock, net proceeds | $ $ 679.1          
Underwriters option | Subsequent Event            
Sale of Stock [Line Items]            
Sale of common stock (in shares) 1,600,000          
Sale of common stock, price (in usd per share) | $ / shares $ 18.00          
Sale of common stock, gross proceeds | $ $ 28.4          
Underwriting discounts and other offering expenses | $ 1.3          
Sale of common stock, net proceeds | $ $ 27.1