Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Schedule of Revenue and Earnings Recognized on Properties Acquired (Detail)

v3.2.0.727
Real Estate and Intangible Assets - Schedule of Revenue and Earnings Recognized on Properties Acquired (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Business Acquisition [Line Items]        
Rental Revenue $ 1,014 $ 896 $ 1,207 $ 910
Earnings 495 431 $ 861 $ 440
Richardson, TX [Member]        
Business Acquisition [Line Items]        
Acquisition Date     Mar. 06, 2015  
Rental Revenue 657   $ 839  
Earnings 90   $ 328  
Birmingham, AL [Member]        
Business Acquisition [Line Items]        
Acquisition Date     Mar. 20, 2015  
Rental Revenue 83   $ 94  
Earnings (22)   $ 106  
Allen, TX [Member]        
Business Acquisition [Line Items]        
Acquisition Date       Mar. 27, 2014
Rental Revenue   142   $ 150
Earnings   81   $ 86
Colleyville, TX [Member]        
Business Acquisition [Line Items]        
Acquisition Date       Mar. 27, 2014
Rental Revenue   117   $ 123
Earnings   67   $ 71
Rancho Cordova, CA [Member]        
Business Acquisition [Line Items]        
Acquisition Date       Apr. 22, 2014
Rental Revenue   173   $ 173
Earnings   65   $ 65
Coppell, TX [Member]        
Business Acquisition [Line Items]        
Acquisition Date       May 08, 2014
Rental Revenue   89   $ 89
Earnings   52   $ 52
Columbus, OH [Member]        
Business Acquisition [Line Items]        
Acquisition Date     May 28, 2015 May 13, 2014
Rental Revenue 67 167 $ 67 $ 167
Earnings 149 68 $ 149 $ 68
Taylor, PA [Member]        
Business Acquisition [Line Items]        
Acquisition Date       Jun. 09, 2014
Rental Revenue   208   $ 208
Earnings   $ 98   $ 98
Salt Lake City, UT [Member]        
Business Acquisition [Line Items]        
Acquisition Date     May 29, 2015  
Rental Revenue 207   $ 207  
Earnings $ 278   $ 278