Agreements and Transactions with Related Parties - Narratives (Details) - USD ($)
12 Months Ended
Aug. 26, 2015
Jul. 14, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Jan. 01, 2017
Mar. 31, 2015
Acquisitions and Disposition Fees              
Preferred return by advisor     5.00%        
Interest rate on unpaid deferred acquisition fees     5.00%        
Asset Management Fees and Available Cash Distributions              
Net asset value (usd per share)       $ 10.24      
Percentage of asset management fees paid in cash     50.00%        
Percentage of asset management fees paid in shares     50.00%   100.00%    
Common stock shares outstanding, shares     343,575,840 337,065,419      
Percentage of available cash distribution to advisor     10.00%        
Personnel And Office Rent Reimbursement              
Maximum personnel and overhead reimbursement, percentage     2.20% 2.40%      
Legal fee reimbursement rate     0.25%        
Line of credit, maximum borrowing capacity $ 250,000,000   $ 200,000,000        
Repayment of notes payable to affiliate     0 $ 25,000,000 $ 0    
Due from affiliate     $ 900,000        
Forecast              
Personnel And Office Rent Reimbursement              
Maximum personnel and overhead reimbursement, percentage           2.00%  
Advisor              
Asset Management Fees and Available Cash Distributions              
Common stock shares outstanding, shares     11,874,009.451        
Percentage of total common stock outstanding held by related party     3.50%        
WPC              
Personnel And Office Rent Reimbursement              
Line of credit, maximum borrowing capacity             $ 75,000,000
Repayment of notes payable to affiliate $ 25,000,000            
WPC | LIBOR              
Personnel And Office Rent Reimbursement              
Basis spread   1.10%          
Average invested assets              
Personnel And Office Rent Reimbursement              
Percentage of operating expenses reimbursements     2.00%        
Adjusted net income              
Personnel And Office Rent Reimbursement              
Percentage of operating expenses reimbursements     25.00%        
Minimum              
Personnel And Office Rent Reimbursement              
Ownership interest, percentage     7.00%        
Minimum | Average equity value              
Asset Management Fees and Available Cash Distributions              
Percentage of asset management fees     1.50%        
Maximum              
Personnel And Office Rent Reimbursement              
Ownership interest, percentage     97.00%        
Maximum | Real estate commission              
Acquisitions and Disposition Fees              
Percentage of subordinated disposition fees     50.00%        
Maximum | Contract sales price of investment              
Acquisitions and Disposition Fees              
Percentage of subordinated disposition fees     3.00%        
Maximum | Average equity value              
Asset Management Fees and Available Cash Distributions              
Percentage of asset management fees     1.75%        
Long-term net lease              
Acquisitions and Disposition Fees              
Percentage of acquisition fees     4.50%        
Long-term net lease | Average market value              
Asset Management Fees and Available Cash Distributions              
Percentage of asset management fees     0.50%        
Long-term net lease | Current              
Acquisitions and Disposition Fees              
Percentage of acquisition fees     2.50%        
Long-term net lease | Deferred              
Acquisitions and Disposition Fees              
Percentage of acquisition fees     2.00%        
Non-long term net lease | Minimum              
Acquisitions and Disposition Fees              
Percentage of acquisition fees     1.00%        
Non-long term net lease | Maximum              
Acquisitions and Disposition Fees              
Percentage of acquisition fees     1.75%        
Real estate              
Related Party Transaction [Line Items]              
Building assumed     $ 97,000,000