Acquisitions of Businesses (Details)
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Nov. 30, 2016
USD ($)
Installment
Feb. 29, 2016
USD ($)
Installment
Dec. 31, 2015
USD ($)
Installment
Aug. 31, 2015
USD ($)
Jun. 30, 2015
USD ($)
Apr. 30, 2015
USD ($)
Installment
Jan. 31, 2015
USD ($)
Installment
Aug. 31, 2014
USD ($)
Apr. 30, 2014
USD ($)
Installment
Mar. 31, 2016
USD ($)
 [1]
Mar. 31, 2015
USD ($)
 [1]
Jun. 30, 2016
USD ($)
 [1]
Jun. 30, 2015
USD ($)
Sep. 30, 2016
USD ($)
 [1]
Sep. 30, 2015
USD ($)
 [1]
Dec. 31, 2016
USD ($)
Clinic
Subsidiary
Operation
Dec. 31, 2015
USD ($)
Clinic
Dec. 31, 2014
USD ($)
Clinic
Business Acquisition [Line Items]                                    
Seller notes issued for acquisition of interest in clinic     $ 1,800,000                         $ 1,000,000 $ 1,800,000 $ 400,000
Number of acquired operations combined | Operation                               2    
Cash paid, net of cash acquired                   $ 12,899,000 $ 6,445,000 $ 12,958,000 $ 14,467,000 [1] $ 12,958,000 $ 14,434,000 $ 23,623,000 18,965,000 [1] 12,270,000 [1]
Seller notes     1,800,000                         1,000,000 1,800,000 400,000
Total consideration     20,765,000                         24,623,000 20,765,000 12,670,000
Estimated fair value of net tangible assets acquired: [Abstract]                                    
Total current assets     1,952,000                         1,712,000 1,952,000 1,213,000
Total non-current assets     1,068,000                         1,202,000 1,068,000 1,051,000
Total liabilities     (1,067,000)                         (398,000) (1,067,000) (406,000)
Net tangible assets acquired     1,953,000                         2,516,000 1,953,000 1,858,000
Referral relationships     3,655,000                         4,919,000 3,655,000 280,000
Non-compete     594,000                         847,000 594,000 330,000
Tradename     3,417,000                         3,802,000 3,417,000 1,600,000
Goodwill     23,437,000                         31,419,000 23,437,000 13,327,000
Fair value of noncontrolling interest     (12,291,000)                         (18,880,000) (12,291,000) (4,725,000)
Total consideration     $ 20,765,000                         $ 24,623,000 $ 20,765,000 $ 12,670,000
Minimum [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired     5.00%                         2.00% 5.00%  
Maximum [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired     35.00%                         35.00% 35.00%  
Referral Relationships [Member] | Minimum [Member]                                    
Business Acquisition [Line Items]                                    
Estimated useful lives of acquired intangibles                               4 years 6 months    
Referral Relationships [Member] | Maximum [Member]                                    
Business Acquisition [Line Items]                                    
Estimated useful lives of acquired intangibles                               13 years    
Non-compete Agreements [Member] | Minimum [Member]                                    
Business Acquisition [Line Items]                                    
Estimated useful lives of acquired intangibles                               5 years    
Non-compete Agreements [Member] | Maximum [Member]                                    
Business Acquisition [Line Items]                                    
Estimated useful lives of acquired intangibles                               6 years    
Tradenames [Member]                                    
Business Acquisition [Line Items]                                    
Estimated useful lives of acquired intangibles                               6 years    
February 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest                               $ 194,000    
February 2018 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest                               $ 194,000    
February 2016 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                               Feb. 29, 2016    
Percentage of interest acquired                               55.00%    
Number of clinics | Clinic                               8    
November 2016 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                               Nov. 30, 2016    
Percentage of interest acquired                               60.00%    
Number of clinics | Clinic                               12    
January 2015 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                 Jan. 31, 2015  
Percentage of interest acquired     60.00%                           60.00%  
Number of clinics | Clinic                                 9  
April 2015 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                 Apr. 30, 2015  
Percentage of interest acquired     70.00%                           70.00%  
Number of clinics | Clinic                                 3  
June 2015 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                 Jun. 30, 2015  
Percentage of interest acquired     70.00%                           70.00%  
Number of clinics | Clinic                                 4  
December 2015 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                 Dec. 31, 2015  
Percentage of interest acquired     59.00%                           59.00%  
Number of clinics | Clinic                                 4  
April 2014 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                   Apr. 30, 2014
Percentage of interest acquired                                   70.00%
Number of clinics | Clinic                                   13
August 2014 Acquisition [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition date                                   Aug. 01, 2014
Percentage of interest acquired                                   100.00%
Number of clinics | Clinic                                   3
Acquisition Of Single Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired     60.00% 60.00%                         60.00%  
Number of clinics | Clinic                               2 1 4
Cash paid for acquisition of interest in clinic       $ 150,000                            
Seller notes issued for acquisition of interest in clinic       50,000                            
Aggregate purchase price for the acquired clinic practices                               $ 75,000    
Number of subsidiaries acquired clinic practices | Subsidiary                               2    
Seller notes       50,000                            
Acquisition Of Single Clinic Practices [Member] | August 2016 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest       $ 50,000                            
Acquisition Of Three Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired           70.00%                        
Cash paid for acquisition of interest in clinic           $ 4,700,000   $ 1,000,000                    
Seller notes issued for acquisition of interest in clinic           $ 150,000                       $ 595,000
Business acquisition number of installments to payment of purchase consideration | Installment           2                        
Seller notes           $ 150,000                       $ 595,000
Acquisition Of Three Clinic Practices [Member] | April 2016 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest           75,000                        
Acquisition Of Three Clinic Practices [Member] | April 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest           $ 75,000                        
Acquisition Of Four Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired     59.00%   70.00%               70.00%       59.00%  
Cash paid for acquisition of interest in clinic     $ 4,600,000   $ 3,600,000                          
Seller notes issued for acquisition of interest in clinic     $ 400,000   700,000               $ 700,000       $ 400,000  
Business acquisition number of installments to payment of purchase consideration | Installment     2                              
Seller notes     $ 400,000   700,000               $ 700,000       $ 400,000  
Acquisition Of Four Clinic Practices [Member] | December 2016 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest     200,000                              
Acquisition Of Four Clinic Practices [Member] | December 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest     $ 200,000                              
Acquisition Of Four Clinic Practices [Member] | June 2018 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest         $ 700,000                          
Acquisition Of Eight Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired   55.00%                                
Cash paid for acquisition of interest in clinic   $ 13,200,000                                
Seller notes issued for acquisition of interest in clinic   $ 500,000                                
Business acquisition number of installments to payment of purchase consideration | Installment   2                                
Seller notes   $ 500,000                                
Acquisition Of Eight Clinic Practices [Member] | February 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest   250,000                                
Acquisition Of Eight Clinic Practices [Member] | February 2018 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest   $ 250,000                                
Acquisition Of Nine Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired             60.00%                      
Cash paid for acquisition of interest in clinic             $ 6,700,000                      
Seller notes issued for acquisition of interest in clinic             $ 500,000                      
Business acquisition number of installments to payment of purchase consideration | Installment             2                      
Seller notes             $ 500,000                      
Acquisition Of Nine Clinic Practices [Member] | January 2016 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest             250,000                      
Acquisition Of Nine Clinic Practices [Member] | January 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest             $ 250,000                      
Acquisition Of Twelve Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired 60.00%                                  
Cash paid for acquisition of interest in clinic $ 11,000,000                                  
Seller notes issued for acquisition of interest in clinic $ 500,000                                  
Business acquisition number of installments to payment of purchase consideration | Installment 2                                  
Seller notes $ 500,000                                  
Acquisition Of Twelve Clinic Practices [Member] | November 2017 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest 250,000                                  
Acquisition Of Twelve Clinic Practices [Member] | November 2018 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest $ 250,000                                  
Acquisition Of Thirteen Clinic Practices [Member]                                    
Business Acquisition [Line Items]                                    
Percentage of interest acquired                 70.00%                  
Cash paid for acquisition of interest in clinic                 $ 10,600,000                  
Seller notes issued for acquisition of interest in clinic                 $ 400,000                  
Business acquisition number of installments to payment of purchase consideration | Installment                 2                  
Seller notes                 $ 400,000                  
Acquisition Of Thirteen Clinic Practices [Member] | April 2016 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest                 200,000                  
Acquisition Of Thirteen Clinic Practices [Member] | April 2015 [Member]                                    
Business Acquisition [Line Items]                                    
Acquisition cost payable in two principal installments including accrued interest                 $ 200,000                  
[1] as restated