Quarterly report pursuant to Section 13 or 15(d)

Nature of Operations and Summary of Significant Accounting Policies - Clinics in Operation Under Franchise Agreements or Company-owned or Managed (Details)

v3.21.2
Nature of Operations and Summary of Significant Accounting Policies - Clinics in Operation Under Franchise Agreements or Company-owned or Managed (Details) - clinic
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Product Information, Franchised Clinics, Company-Owned Or Managed Clinics, Activity [Roll Forward]        
Closed during the period     0 0
Clinics in operation at the end of the period 633 539 633 539
Clinic licenses sold but not yet developed 247 169 247 169
Executed letters of intent for future clinic licenses 35 40 35 40
Franchised Clinics        
Product Information, Franchised Clinics, Company-Owned Or Managed Clinics, Activity [Roll Forward]        
Clinics open at beginning of period 527 469 515 453
Opened during the period 36 12 48 28
Sold during the period (8) 0 (8) 0
Closed during the period 0 (4) 0 (4)
Clinics in operation at the end of the period 555 477 555 477
Company-owned or Managed Clinics        
Product Information, Franchised Clinics, Company-Owned Or Managed Clinics, Activity [Roll Forward]        
Clinics open at beginning of period 65 61 64 60
Opened during the period 5 1 6 2
Acquired during the period 8 0 8 0
Closed during the period 0 0    
Clinics in operation at the end of the period 78 62 78 62