Significant Accounting Policies (Details)
 1 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
May 31, 2017
USD ($)
Clinic
Mar. 31, 2017
USD ($)
Jan. 31, 2017
USD ($)
Clinic
Sep. 30, 2016
USD ($)
 [1]
Jun. 30, 2016
USD ($)
 [1]
Mar. 31, 2016
USD ($)
 [1]
Sep. 30, 2015
USD ($)
 [1]
Jun. 30, 2015
USD ($)
 [1]
Mar. 31, 2015
USD ($)
 [1]
Jun. 30, 2016
USD ($)
 [1]
Jun. 30, 2015
USD ($)
 [1]
Sep. 30, 2016
USD ($)
 [1]
Sep. 30, 2015
USD ($)
 [1]
Dec. 31, 2016
USD ($)
Segment
Region
$ / shares
Dec. 31, 2015
USD ($)
Region
Dec. 31, 2014
USD ($)
Region
Depreciation Amortization Impairment [Line Items]                                
Number of business segments | Segment                           1    
Number of regions | Region                           6 6 6
Federal debt ceiling in connection with deficit reductions                           10 years    
Reductions in federal spending                           $ 1,200,000,000,000    
Medicare spending cut percentage                           2.00%    
Expected reduction in Medicare spending percentage                           2.00%    
Combined physical therapy/speech language pathology expenses                           $ 3,700    
Percentage of practice expense component                           100.00%    
Percentage reduction for service                           50.00%    
Net revenue from Medicare accounts                           $ 81,800,000    
Difference between net revenues and corresponding cash collections, approximately of net revenues                           1.00%    
Difference between actual aggregate contractual reserve and estimated contractual allowance reserve percentage                           1.00%    
Maximum contractual allowance reserve estimate                           1.00%    
Minimum percentage of fair value reporting unit less than carrying amount                           50.00%    
Unrecognized tax benefit                           $ 0 $ 0  
Accrued interest and penalties associated with any unrecognized tax benefits                           0 0 $ 0
Interest expense recognized                           0 0  
Increase in earnings by decreasing the tax provision due to adoption of new accounting treatment       $ 2,753,000 $ 3,802,000 $ 2,172,000 $ 3,465,000 $ 4,221,000 $ 2,685,000 $ 5,974,000 $ 6,906,000 $ 8,727,000 $ 10,371,000 11,880,000 $ 13,647,000 [1] $ 13,018,000 [1]
Accounting Standards Update 2016-09 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Increase in earnings by decreasing the tax provision due to adoption of new accounting treatment                           $ 1,000,000    
Increase in earnings by decreasing the tax provision due to adoption of new accounting treatment (in dollars per share) | $ / shares                           $ 0.09    
Physical Therapy Practice [Member] | Subsequent Event [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of interest acquired 70.00%   70.00%                          
Number of clinics owned and operated | Clinic 4   17                          
Number of additional clinics managed | Clinic     8                          
Purchase price $ 2,500,000   $ 11,400,000                          
Workforce Performance Solutions [Member] | Subsequent Event [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of interest acquired   55.00%                            
Purchase price   $ 6,600,000                            
Year 2016 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of medicare payment                           (0.30%)    
Expected reduction in Medicare spending percentage                           2.00%    
Year 2017 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of payment adjustments proposed by CMS                           (0.08%)    
Expected reduction in Medicare spending percentage                           2.00%    
January 1, 2015 through June 30, 2015 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of medicare payment                           0.00%    
July 1, 2015 through December 31, 2015 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of medicare payment                           0.50%    
From 2017 through 2019 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Percentage of medicare payment                           0.50%    
Minimum [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Redemption period in the limited partnership agreement                           3 years    
Percentage of interest acquired                           2.00% 5.00%  
Minimum [Member] | Furniture & Equipment [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           3 years    
Minimum [Member] | Computer Software, Intangible Asset [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           3 years    
Minimum [Member] | Leasehold Improvements [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           3 years    
Maximum [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Redemption period in the limited partnership agreement                           5 years    
Percentage of interest acquired                           35.00% 35.00%  
Maximum [Member] | Year 2016 [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Annual limit on physical therapy and speech language pathology services                           $ 1,960    
Annual limit occupational therapy services                           $ 1,960    
Maximum [Member] | Furniture & Equipment [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           8 years    
Maximum [Member] | Computer Software, Intangible Asset [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           7 years    
Maximum [Member] | Leasehold Improvements [Member]                                
Depreciation Amortization Impairment [Line Items]                                
Estimated useful lives                           5 years    
[1] as restated