Related-Party Transactions and Arrangements (Narrative) (Details)
2 Months Ended 3 Months Ended 10 Months Ended 11 Months Ended 12 Months Ended
Apr. 11, 2019
Mar. 31, 2019
USD ($)
employee
Dec. 31, 2018
USD ($)
employee
Nov. 27, 2018
Nov. 24, 2017
Mar. 14, 2018
Mar. 31, 2019
USD ($)
employee
Mar. 31, 2018
USD ($)
Dec. 31, 2018
employee
Nov. 27, 2018
Dec. 31, 2018
USD ($)
employee
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Related Party Transaction [Line Items]                          
Number of employees | employee   0 0       0   0   0    
Payments of offering costs             $ 1,036,000 $ 3,672,000     $ 12,388,000 $ 32,079,000 $ 30,628,000
Expenses incurred from transactions with related party             $ 5,513,000 8,288,000     $ 31,633,000 65,351,000 55,111,000
Annual cumulative, non-compounded return on capital threshold to investors             6.00%       6.00%    
Subsequent Event [Member]                          
Related Party Transaction [Line Items]                          
Annual cumulative, non-compounded return on capital threshold to investors 8.00%                        
Maximum [Member]                          
Related Party Transaction [Line Items]                          
Disposition fee (% of contract sales price)             6.00%       6.00%    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member]                          
Related Party Transaction [Line Items]                          
Acquisition fee (% of contract purchase price of each property or asset acquired)             2.00%       2.00%    
Acquisition expenses reimbursed (% of purchase price of each property or real estate-related investment)   0.01% 0.01%                    
Subordinated participation in net sale proceeds, percentage             15.00%       15.00%    
Subordinated incentive listing fee, percentage             15.00%       15.00%    
Subordinated termination fee, percentage             15.00%       15.00%    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Other Offering Costs [Member]                          
Related Party Transaction [Line Items]                          
Payments of offering costs   $ 19,269,000 $ 19,192,000                    
Expenses incurred from transactions with related party             $ 0 $ 647,000     $ 2,154,000 4,704,000 $ 4,428,000
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Disposition Fees [Member]                          
Related Party Transaction [Line Items]                          
Expenses incurred from transactions with related party   0 0                    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Subordinated Participation In Net Sale Proceeds [Member]                          
Related Party Transaction [Line Items]                          
Expenses incurred from transactions with related party   0 0                    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Subordinated Incentive Listing Fee [Member]                          
Related Party Transaction [Line Items]                          
Expenses incurred from transactions with related party   0 0                    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Subordinated Termination Fee [Member]                          
Related Party Transaction [Line Items]                          
Expenses incurred from transactions with related party   0 0                    
Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Maximum [Member]                          
Related Party Transaction [Line Items]                          
Disposition fee (% of contract sales price)             1.00%       1.00%    
Disposition fee (% of third party brokerage commission)             50.00%       50.00%    
Affiliate of Dealer Manager [Member] | Other Offering Costs [Member]                          
Related Party Transaction [Line Items]                          
Payments of offering costs   $ 548,000 $ 542,000                    
SC Distributors, LLC [Member] | Class I shares [Member]                          
Related Party Transaction [Line Items]                          
Dealer manager fee (% of gross offering proceeds)                   1.00%      
Dealer manager fee funded by advisor (% of gross offering proceeds)                   1.00%      
SC Distributors, LLC [Member] | Maximum [Member] | Class A shares [Member]                          
Related Party Transaction [Line Items]                          
Selling commission (% of gross offering proceeds)                   7.00%      
Dealer manager fee (% of gross offering proceeds)                   3.00%      
SC Distributors, LLC [Member] | Maximum [Member] | Class I shares [Member]                          
Related Party Transaction [Line Items]                          
Dealer manager fee (% of gross offering proceeds)                   2.00%      
SC Distributors, LLC [Member] | Maximum [Member] | Class T shares [Member]                          
Related Party Transaction [Line Items]                          
Selling commission (% of gross offering proceeds)           3.00%              
Dealer manager fee (% of gross offering proceeds)           3.00%              
SC Distributors, LLC [Member] | Maximum [Member] | Class T2 shares [Member]                          
Related Party Transaction [Line Items]                          
Selling commission (% of gross offering proceeds)                 3.00%        
Dealer manager fee (% of gross offering proceeds)                 2.50%        
Carter Validus Real Estate Management Services II, LLC [Member]                          
Related Party Transaction [Line Items]                          
Property management fee (% of gross revenues from properties managed)             3.00%       3.00%    
Oversight fee (% of gross revenues from properties managed)             1.00%       1.00%    
Construction management fee (% of project costs)             5.00%       5.00%    
Carter Validus Advisors II, LLC [Member]                          
Related Party Transaction [Line Items]                          
Monthly asset management fee (% of aggregate asset value)             0.0625%       0.0625%    
Carter Validus Advisors II, LLC [Member] | Maximum [Member]                          
Related Party Transaction [Line Items]                          
Operating expense reimbursement (% of average invested assets)             2.00%       2.00%    
Operating expense reimbursement ( % of net income)             25.00%       25.00%    
Vice President of Product Management of Carter Validus Advisors II, LLC [Member] | Other Offering Costs [Member]                          
Related Party Transaction [Line Items]                          
Expenses incurred from transactions with related party                     $ 69,000 $ 98,000  
Initial Offering and Follow-On Offering [Member] | Carter Validus Advisors II, LLC And/Or Its Affiliates [Member] | Maximum [Member]                          
Related Party Transaction [Line Items]                          
Organization and offering expenses (% of gross offering proceeds)             15.00%       15.00%    
Initial Offering [Member] | Carter Validus Advisors II, LLC And/Or Its Affiliates [Member]                          
Related Party Transaction [Line Items]                          
Other offering costs reimbursed (% of gross offering proceeds)         2.00%                
Follow-On Offering [Member] | Carter Validus Advisors II, LLC And/Or Its Affiliates [Member]                          
Related Party Transaction [Line Items]                          
Other offering costs reimbursed (% of gross offering proceeds)       2.50%