Debt Transactions - Additional Information (Detail)
 1 Months Ended 9 Months Ended
Sep. 30, 2016
USD ($)
Community
Sep. 27, 2016
USD ($)
Sep. 23, 2016
USD ($)
Community
Aug. 02, 2016
USD ($)
Community
Jun. 15, 2016
USD ($)
Community
May 03, 2016
USD ($)
Feb. 16, 2016
USD ($)
Jan. 26, 2016
USD ($)
Jul. 31, 2016
USD ($)
Community
Sep. 30, 2016
USD ($)
Community
Dec. 31, 2015
USD ($)
Oct. 30, 2015
Aug. 11, 2015
Debt Instrument [Line Items]                          
Mortgage debt $ 873,500,000                 $ 873,500,000 $ 775,200,000    
Fixed interest rate                       4.25%  
Deferred financing cost $ 12,200,000                 $ 12,200,000 10,300,000    
Senior housing communities operated by company | Community 128                 128      
Net book value of housing communities $ 914,000,000                 $ 914,000,000 818,700,000    
Accumulated amortization $ 2,700,000                 $ 2,700,000 $ 1,800,000    
4.98% [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt         $ 16,900,000                
Fixed interest rate         4.98%                
Deferred financing cost         $ 500,000                
Mortgage debt maturity         2024-07                
4.98% [Member] | Texas [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Senior housing communities operated by company | Community         4                
4.98% [Member] | Ohio [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Senior housing communities operated by company | Community         2                
4.98% [Member] | Missouri [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Senior housing communities operated by company | Community         1                
4.85% [Member] | Texas [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt     $ 3,800,000                    
Fixed interest rate     4.85%                    
Deferred financing cost     $ 100,000                    
Mortgage debt maturity     2022-05                    
Senior housing communities operated by company | Community     1                    
4.85% [Member] | Indiana [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt     $ 3,500,000                    
Fixed interest rate     4.85%                    
Deferred financing cost     $ 100,000                    
Mortgage debt maturity     2022-04                    
Senior housing communities operated by company | Community     1                    
4.97% [Member] | Texas [Member] | Fannie Mae [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt       $ 2,100,000                  
Fixed interest rate       4.97%                  
Deferred financing cost       $ 100,000                  
Mortgage debt maturity       2022-04                  
Senior housing communities operated by company | Community       1                  
Variable Interest Rate LIBOR Plus 4.5% Loan [Member] | Ohio [Member] | Berkadia Commercial Mortgage LLC [Member]                          
Debt Instrument [Line Items]                          
Deferred financing cost                 $ 29,500        
Deferred financing costs amortization period                 25 years        
Senior housing communities operated by company | Community                 1        
Debt instrument maturity date                 Jul. 10, 2018        
Debt instrument variable interest rate description                   LIBOR plus 4.50%      
Debt instrument variable interest rate                 4.50%        
Pensacola Transaction [Member] | 4.38 % [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt             $ 35,000,000            
Term period of mortgage loans             10 years            
Fixed interest rate             4.38%            
Term period of principal amortized             30 years            
Deferred financing cost             $ 400,000            
Deferred financing costs amortization period             10 years            
Pine Ridge Transaction [Member] | 4.38 % [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt               $ 11,300,000          
Term period of mortgage loans               10 years          
Fixed interest rate               4.50%          
Term period of principal amortized               30 years          
Deferred financing cost               $ 200,000          
Deferred financing costs amortization period               10 years          
Indianapolis Transaction [Member]                          
Debt Instrument [Line Items]                          
Fixed interest rate           4.25%             4.25%
Indianapolis Transaction [Member] | 4.25 % [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt           $ 2,600,000              
Term period of mortgage loans           10 years              
Springfield Massachusetts [Member]                          
Debt Instrument [Line Items]                          
Fixed interest rate 4.10%                 4.10%      
Springfield Massachusetts [Member] | 4.10% [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt $ 20,300,000                 $ 20,300,000      
Term period of mortgage loans 10 years                        
Fixed interest rate 4.10%                 4.10%      
Term period of principal amortized 30 years                        
Deferred financing cost $ 200,000                 $ 200,000      
Deferred financing costs amortization period 10 years                        
Kingwood Texas [Member]                          
Debt Instrument [Line Items]                          
Fixed interest rate   4.13%                      
Kingwood Texas [Member] | 4.13% [Member]                          
Debt Instrument [Line Items]                          
Mortgage debt   $ 13,000,000                      
Term period of mortgage loans   15 years                      
Fixed interest rate   4.13%                      
Term period of principal amortized   30 years                      
Deferred financing cost   $ 200,000                      
Deferred financing costs amortization period   15 years                      
Hartford Financial Services [Member]                          
Debt Instrument [Line Items]                          
Letters of credit $ 3,900,000                 3,900,000      
Welltower, Inc. [Member]                          
Debt Instrument [Line Items]                          
Letters of credit 6,600,000                 6,600,000      
HCP, Inc. [Member]                          
Debt Instrument [Line Items]                          
Letters of credit $ 2,700,000                 $ 2,700,000