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           Real Estate and Intangible Assets - Summary Information of Twenty-One Farms (Detail) (USD $) 
         | 
        3 Months Ended | 0 Months Ended | 3 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 
           Mar. 31, 2014
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2013
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          San Andreas [Member]
 
          Watsonville, CA [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          West Gonzales [Member]
 
          Oxnard, CA [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 27, 2014
 
          West Beach [Member] 
         | 
        
           Mar. 31, 2014
 
          West Beach [Member]
 
          Watsonville, CA [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          Dalton Lane [Member]
 
          Watsonville, CA [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          Keysville Road [Member]
 
          Plant City, FL [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          Colding Loop [Member]
 
          Wimauma, FL [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          Trapnell Road [Member]
 
          Plant City, FL [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          38th Avenue [Member]
 
          Covert, MI [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          Sequoia Street [Member]
 
          Brooks, OR [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          Natividad Road [Member]
 
          Salinas, CA [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          20th Avenue [Member]
 
          South Haven, MI [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          Broadway Road [Member]
 
          Moorpark, CA [Member]
 
          Farm
 
          acre 
         | 
        
           Mar. 31, 2014
 
          Oregon Trail [Member]
 
          Echo, OR [Member]
 
          acre
 
          Farm 
         | 
        
           Mar. 31, 2014
 
          East Shelton [Member]
 
          Willcox, AZ [Member]
 
          acre
 
          Farm 
         | 
      |
| Business Acquisition [Line Items] | |||||||||||||||||
| Date Acquired | Jun. 16, 1997 | Sep. 15, 1998 | Jan. 03, 2011 | Jul. 07, 2011 | Oct. 26, 2011 | Aug. 09, 2012 | Sep. 12, 2012 | Apr. 05, 2013 | May 31, 2013 | Oct. 21, 2013 | Nov. 05, 2013 | Dec. 16, 2013 | Dec. 27, 2013 | Dec. 27, 2013 | |||
| Number of Farms | 21 | 12 | 1 | 1 | 3 | 1 | 2 | 1 | 3 | 1 | 1 | 1 | 3 | 1 | 1 | 1 | |
| Total Acres | 6,000 | 1,630 | 307 | 653 | 196 | 72 | 59 | 219 | 124 | 119 | 218 | 166 | 151 | 60 | 1,895 | 1,761 | |
| Farmable Acres | 4,920 | 237 | 502 | 195 | 70 | 50 | 181 | 110 | 89 | 206 | 166 | 94 | 60 | 1,640 | 1,320 | ||
| Lease Expiration Date | Dec. 31, 2014 | Jun. 30, 2020 | Dec. 31, 2023 | Dec. 31, 2023 | Oct. 31, 2015 | Jul. 01, 2016 | Jun. 14, 2018 | Jun. 30, 2017 | Apr. 04, 2020 | May 31, 2028 | Oct. 31, 2024 | Apr. 11, 2018 | Dec. 15, 2023 | Dec. 31, 2023 | Feb. 29, 2024 | ||
| Net Cost Basis | $ 75,979,461 | $ 4,855,100 | $ 12,339,049 | $ 8,383,970 | $ 2,718,326 | $ 1,230,758 | $ 3,980,623 | $ 4,227,983 | $ 1,343,135 | $ 3,176,000 | $ 7,456,086 | $ 1,994,669 | $ 3,001,717 | $ 14,049,596 | $ 7,222,449 | ||
| Encumbrances | $ 41,431,998 | $ 100,000 | $ 26,784,299 | $ 4,997,773 | $ 1,648,264 | $ 880,644 | $ 2,089,764 | $ 2,317,577 | $ 788,813 | $ 1,824,864 | |||||||