Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail)

v3.20.2
Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail) - $ / shares
Oct. 07, 2020
Oct. 05, 2020
Sep. 30, 2020
Sep. 23, 2020
Sep. 04, 2020
Aug. 31, 2020
Aug. 26, 2020
Aug. 24, 2020
Aug. 05, 2020
Jul. 31, 2020
Jul. 29, 2020
Jul. 24, 2020
Jul. 14, 2020
Subsequent Event | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         $ 0.4374999
Subsequent Event | Series E Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         0.414063
Subsequent Event | Series F Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         0.375
Subsequent Event | Senior Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         0.2625
Subsequent Event | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         $ 0.37545
Subsequent Event | July 2020                          
Dividends Payable [Line Items]                          
Record Date                       Jul. 24, 2020  
Forecast | August 2020                          
Dividends Payable [Line Items]                          
Record Date               Aug. 24, 2020          
Payment Date           Aug. 31, 2020              
Forecast | August 2020 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)           $ 0.1458333              
Forecast | August 2020 | Series E Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)           0.138021              
Forecast | August 2020 | Series F Preferred Stock                          
Dividends Payable [Line Items]                          
Record Date             Aug. 26, 2020            
Payment Date         Sep. 04, 2020                
Distribution per share (in dollars per share)         $ 0.125                
Forecast | August 2020 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payment Date         Sep. 04, 2020                
Distribution per share (in dollars per share)         $ 0.0875                
Forecast | August 2020 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)           $ 0.12515              
Forecast | September 2020                          
Dividends Payable [Line Items]                          
Record Date       Sep. 23, 2020                  
Payment Date     Sep. 30, 2020                    
Forecast | September 2020 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)     $ 0.1458333                    
Forecast | September 2020 | Series E Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)     $ 0.138021                    
Forecast | September 2020 | Series F Preferred Stock                          
Dividends Payable [Line Items]                          
Record Date     Sep. 30, 2020                    
Payment Date Oct. 07, 2020                        
Distribution per share (in dollars per share) $ 0.125                        
Forecast | September 2020 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payment Date   Oct. 05, 2020                      
Distribution per share (in dollars per share)   $ 0.0875                      
Forecast | September 2020 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)     $ 0.12515                    
Forecast | Subsequent Event | July 2020                          
Dividends Payable [Line Items]                          
Payment Date                   Jul. 31, 2020      
Forecast | Subsequent Event | July 2020 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                   $ 0.1458333      
Forecast | Subsequent Event | July 2020 | Series E Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                   0.138021      
Forecast | Subsequent Event | July 2020 | Series F Preferred Stock                          
Dividends Payable [Line Items]                          
Record Date                     Jul. 29, 2020    
Payment Date                 Aug. 05, 2020        
Distribution per share (in dollars per share)                 $ 0.125        
Forecast | Subsequent Event | July 2020 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payment Date                 Aug. 05, 2020        
Distribution per share (in dollars per share)                 $ 0.0875        
Forecast | Subsequent Event | July 2020 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                   $ 0.12515