Subsequent Events (Narrative) (Details) - USD ($)
 3 Months Ended 8 Months Ended 12 Months Ended
May 10, 2019
Apr. 11, 2019
Mar. 01, 2019
Feb. 26, 2019
Feb. 01, 2019
Jan. 02, 2019
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Apr. 26, 2018
Subsequent Event [Line Items]                          
Distributions paid in cash             $ 10,813,000 $ 9,333,000   $ 40,296,000 $ 28,994,000 $ 17,659,000  
Common stock issued through distribution reinvestment plan             $ 10,385,000 $ 9,920,000   $ 40,938,000 $ 32,264,000 $ 22,889,000  
Distributions declared per common share (in dollars per share)             $ 0.16 $ 0.15   $ 0.63 $ 0.62    
Common stock, par value (in dollars per share)             $ 0.01   $ 0.01 $ 0.01 $ 0.01    
Annual cumulative, non-compounded return on capital threshold to investors             6.00%     6.00%      
Credit facility, recourse debt restriction percentage             15.00%            
Credit facility, maximum borrowing capacity                 $ 700,000,000 $ 700,000,000     $ 425,000,000
Minimum [Member]                          
Subsequent Event [Line Items]                          
Credit facility, ticking fee (as % of facility)                   0.15%      
Minimum [Member] | Base Rate [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin                 0.75%        
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin                 1.75%        
Maximum [Member]                          
Subsequent Event [Line Items]                          
Credit facility, ticking fee (as % of facility)                   0.25%      
Maximum [Member] | Base Rate [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin                 1.25%        
Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin                 2.25%        
Class A shares [Member]                          
Subsequent Event [Line Items]                          
Common stock, par value (in dollars per share)             $ 0.01            
Subsequent Event [Member]                          
Subsequent Event [Line Items]                          
Annual cumulative, non-compounded return on capital threshold to investors   8.00%                      
Credit facility, recourse debt restriction percentage   17.50%                      
Subsequent Event [Member] | Management Agreement [Member] | Carter Validus Real Estate Management Services II, LLC [Member]                          
Subsequent Event [Line Items]                          
Term of agreement 1 year                        
Subsequent Event [Member] | Advisory Agreement [Member] | Carter Validus Advisors II, LLC [Member]                          
Subsequent Event [Line Items]                          
Term of agreement 1 year                        
Subsequent Event [Member] | Bridge Facility [Member]                          
Subsequent Event [Line Items]                          
Credit facility, maximum borrowing capacity   $ 475,000,000                      
Credit facility, term   6 months                      
Credit facility, underwriting fee and commitment fee (as % of facility)   0.50%                      
Credit facility, funding fee (as % of funded facility)   0.50%                      
Credit facility, ticking fee (as % of facility)   0.12%                      
Subsequent Event [Member] | Bridge Facility [Member] | Base Rate [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin   1.25%                      
Credit facility, increases to applicable margin during basis spread increase period   0.25%                      
Credit facility, basis spread increase period   90 days                      
Subsequent Event [Member] | Bridge Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin   2.25%                      
Credit facility, increases to applicable margin during basis spread increase period   0.25%                      
Credit facility, basis spread increase period   90 days                      
Subsequent Event [Member] | Maximum [Member] | Bridge Facility [Member]                          
Subsequent Event [Line Items]                          
Credit facility, structuring fee   $ 350,000                      
Credit facility, structuring fee (as % of facility)   0.10%                      
Subsequent Event [Member] | Maximum [Member] | Bridge Facility [Member] | Federal Funds Effective Swap Rate [Member]                          
Subsequent Event [Line Items]                          
Credit facility, applicable margin   0.50%                      
Subsequent Event [Member] | Maximum [Member] | Bridge Facility [Member] | Base Rate [Member]                          
Subsequent Event [Line Items]                          
Credit facility, interest rate   1.00%                      
Subsequent Event [Member] | Carter Validus Mission Critical REIT, Inc. [Member]                          
Subsequent Event [Line Items]                          
Common stock, par value (in dollars per share)   $ 0.01                      
Business acquisition, cash paid per common share (in dollars per share)   $ 1.00                      
Business acquisition, termination period   5 days                      
Subsequent Event [Member] | Carter Validus Mission Critical REIT, Inc. [Member] | Minimum [Member]                          
Subsequent Event [Line Items]                          
Business acquisition, termination fee   $ 14,400,000                      
Subsequent Event [Member] | Carter Validus Mission Critical REIT, Inc. [Member] | Maximum [Member]                          
Subsequent Event [Line Items]                          
Business acquisition, termination fee   $ 28,800,000                      
Subsequent Event [Member] | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Business acquisition, stock conversion ratio   0.4681                      
Subsequent Event [Member] | December 1, 2018 To December 31, 2018 [Member]                          
Subsequent Event [Line Items]                          
Distributions paid in cash           $ 3,715,000              
Common stock issued through distribution reinvestment plan           3,602,000              
Subsequent Event [Member] | December 1, 2018 To December 31, 2018 [Member] | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid           4,613,000              
Distributions paid in cash           2,432,000              
Common stock issued through distribution reinvestment plan           2,181,000              
Subsequent Event [Member] | December 1, 2018 To December 31, 2018 [Member] | Class I shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid           698,000              
Distributions paid in cash           404,000              
Common stock issued through distribution reinvestment plan           294,000              
Subsequent Event [Member] | December 1, 2018 To December 31, 2018 [Member] | Class T shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid           1,842,000              
Distributions paid in cash           810,000              
Common stock issued through distribution reinvestment plan           1,032,000              
Subsequent Event [Member] | December 1, 2018 To December 31, 2018 [Member] | Class T2 shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid           164,000              
Distributions paid in cash           69,000              
Common stock issued through distribution reinvestment plan           $ 95,000              
Subsequent Event [Member] | January 1, 2019 To January 31, 2019 [Member] | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid         $ 4,594,000                
Distributions paid in cash         2,439,000                
Common stock issued through distribution reinvestment plan         2,155,000                
Subsequent Event [Member] | January 1, 2019 To January 31, 2019 [Member] | Class I shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid         696,000                
Distributions paid in cash         404,000                
Common stock issued through distribution reinvestment plan         292,000                
Subsequent Event [Member] | January 1, 2019 To January 31, 2019 [Member] | Class T shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid         1,840,000                
Distributions paid in cash         813,000                
Common stock issued through distribution reinvestment plan         1,027,000                
Subsequent Event [Member] | January 1, 2019 To January 31, 2019 [Member] | Class T2 shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid         165,000                
Distributions paid in cash         70,000                
Common stock issued through distribution reinvestment plan         $ 95,000                
Subsequent Event [Member] | February 1, 2019 To February 28, 2019 | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid     $ 4,146,000                    
Distributions paid in cash     2,205,000                    
Common stock issued through distribution reinvestment plan     1,941,000                    
Subsequent Event [Member] | February 1, 2019 To February 28, 2019 | Class I shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid     628,000                    
Distributions paid in cash     365,000                    
Common stock issued through distribution reinvestment plan     263,000                    
Subsequent Event [Member] | February 1, 2019 To February 28, 2019 | Class T shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid     1,665,000                    
Distributions paid in cash     740,000                    
Common stock issued through distribution reinvestment plan     925,000                    
Subsequent Event [Member] | February 1, 2019 To February 28, 2019 | Class T2 shares [Member]                          
Subsequent Event [Line Items]                          
Aggregate distributions paid     149,000                    
Distributions paid in cash     63,000                    
Common stock issued through distribution reinvestment plan     $ 86,000                    
Subsequent Event [Member] | March 1, 2019 To May 31, 2019 [Member] | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation       365 days                  
Distributions declared per common share (in dollars per share)       $ 0.001802170                  
Annualized distribution rate       6.40%                  
Purchase price (in dollars per share)       $ 10.278                  
Subsequent Event [Member] | March 1, 2019 To May 31, 2019 [Member] | Class I shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation       365 days                  
Distributions declared per common share (in dollars per share)       $ 0.001802170                  
Annualized distribution rate       7.04%                  
Purchase price (in dollars per share)       $ 9.343                  
Subsequent Event [Member] | March 1, 2019 To May 31, 2019 [Member] | Class T shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation       365 days                  
Distributions declared per common share (in dollars per share)       $ 0.001561644                  
Annualized distribution rate       5.79%                  
Purchase price (in dollars per share)       $ 9.840                  
Subsequent Event [Member] | March 1, 2019 To May 31, 2019 [Member] | Class T2 shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation       365 days                  
Distributions declared per common share (in dollars per share)       $ 0.001561644                  
Annualized distribution rate       5.82%                  
Purchase price (in dollars per share)       $ 9.788                  
Subsequent Event [Member] | June 1, 2019 To August 31, 2019 [Member] | Class A shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation 365 days                        
Distributions declared per common share (in dollars per share) $ 0.001802170                        
Annualized distribution rate 6.40%                        
Purchase price (in dollars per share) $ 10.278                        
Subsequent Event [Member] | June 1, 2019 To August 31, 2019 [Member] | Class I shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation 365 days                        
Distributions declared per common share (in dollars per share) $ 0.001802170                        
Annualized distribution rate 7.04%                        
Purchase price (in dollars per share) $ 9.343                        
Subsequent Event [Member] | June 1, 2019 To August 31, 2019 [Member] | Class T shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation 365 days                        
Distributions declared per common share (in dollars per share) $ 0.001561644                        
Annualized distribution rate 5.79%                        
Purchase price (in dollars per share) $ 9.840                        
Subsequent Event [Member] | June 1, 2019 To August 31, 2019 [Member] | Class T2 shares [Member]                          
Subsequent Event [Line Items]                          
Number of days, distribution calculation 365 days                        
Distributions declared per common share (in dollars per share) $ 0.001561644                        
Annualized distribution rate 5.82%                        
Purchase price (in dollars per share) $ 9.788