Quarterly report pursuant to Section 13 or 15(d)

Equity - Monthly Distributions Declared and Paid by Company's Board of Directors (Detail)

v3.7.0.1
Equity - Monthly Distributions Declared and Paid by Company's Board of Directors (Detail) - $ / shares
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Class of Stock [Line Items]    
Distributions per Common Share (in dollars per share) $ 0.129 $ 0.12
2017-01-31    
Class of Stock [Line Items]    
Declaration Date Jan. 10, 2017  
Record Date Jan. 20, 2017  
Payment Date Jan. 31, 2017  
Distributions per Common Share (in dollars per share) $ 0.043  
2017-02-28    
Class of Stock [Line Items]    
Declaration Date Jan. 10, 2017  
Record Date Feb. 16, 2017  
Payment Date Feb. 28, 2017  
Distributions per Common Share (in dollars per share) $ 0.043  
2017-03-31    
Class of Stock [Line Items]    
Declaration Date Jan. 10, 2017  
Record Date Mar. 22, 2017  
Payment Date Mar. 31, 2017  
Distributions per Common Share (in dollars per share) $ 0.043  
2016-02-02    
Class of Stock [Line Items]    
Declaration Date   Jan. 12, 2016
Record Date   Jan. 22, 2016
Payment Date   Feb. 02, 2016
Distributions per Common Share (in dollars per share)   $ 0.040
2016-02-29    
Class of Stock [Line Items]    
Declaration Date   Jan. 12, 2016
Record Date   Feb. 18, 2016
Payment Date   Feb. 29, 2016
Distributions per Common Share (in dollars per share)   $ 0.040
2016-03-31    
Class of Stock [Line Items]    
Declaration Date   Jan. 12, 2016
Record Date   Mar. 21, 2016
Payment Date   Mar. 31, 2016
Distributions per Common Share (in dollars per share)   $ 0.040