Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.2
Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail) - $ / shares
 1 Months Ended
Oct. 07, 2019
Sep. 30, 2019
Sep. 17, 2019
Sep. 06, 2019
Aug. 30, 2019
Aug. 20, 2019
Aug. 07, 2019
Jul. 31, 2019
Jul. 22, 2019
Sep. 30, 2019
Aug. 31, 2019
Jul. 31, 2019
Jul. 09, 2019
Subsequent event | Series A Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         $ 0.4843749
Subsequent event | Series B Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         0.46875
Subsequent event | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)                         0.4374999
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)                         $ 0.375
Subsequent event | April 2019                          
Dividends Payable [Line Items]                          
Record Date                 Jul. 22, 2019        
Forecast | April 2019                          
Dividends Payable [Line Items]                          
Payment Date               Jul. 31, 2019          
Forecast | April 2019 | Series A Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)               $ 0.1614583       $ 0.1614583  
Forecast | April 2019 | Series B Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)               0.15625       0.15625  
Forecast | April 2019 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)               0.1458333       $ 0.1458333  
Forecast | April 2019 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payable to the Holders of Record During the Month of:                       July  
Payment Date             Aug. 07, 2019            
Distribution per share (in dollars per share)             $ 0.0875            
Forecast | April 2019 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)               $ 0.125       $ 0.125  
Forecast | May 2019                          
Dividends Payable [Line Items]                          
Record Date           Aug. 20, 2019              
Payment Date         Aug. 30, 2019                
Forecast | May 2019 | Series A Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)         $ 0.1614583                
Forecast | May 2019 | Series B Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)         0.15625                
Forecast | May 2019 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)         0.1458333                
Forecast | May 2019 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payable to the Holders of Record During the Month of:                     August    
Payment Date       Sep. 06, 2019                  
Distribution per share (in dollars per share)       $ 0.0875                  
Forecast | May 2019 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)         $ 0.125                
Forecast | June 2019                          
Dividends Payable [Line Items]                          
Record Date     Sep. 17, 2019                    
Payment Date   Sep. 30, 2019                      
Forecast | June 2019 | Series A Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)   $ 0.1614583               $ 0.1614583      
Forecast | June 2019 | Series B Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)   0.15625               0.15625      
Forecast | June 2019 | Series D Preferred Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)   0.1458333               $ 0.1458333      
Forecast | June 2019 | Senior Common Stock                          
Dividends Payable [Line Items]                          
Payable to the Holders of Record During the Month of:                   September      
Payment Date Oct. 07, 2019                        
Distribution per share (in dollars per share) $ 0.0875                        
Forecast | June 2019 | Common Stock                          
Dividends Payable [Line Items]                          
Distribution per share (in dollars per share)   $ 0.125               $ 0.125