Investment in Leases (Detail) (USD $)
In Thousands, unless otherwise specified
 6 Months Ended
Jun. 30, 2012
Leases Disclosure [Line Items]  
Balance December 31, 2011 $ 8,276
Reclassifications & Additions / Dispositions (38)
Depreciation/ Amortization Expense or Amortization of Leases (657)
Balance June 30, 2012 7,581
Operating leases
  
Leases Disclosure [Line Items]  
Balance December 31, 2011 7,867
Reclassifications & Additions / Dispositions (832)
Depreciation/ Amortization Expense or Amortization of Leases (571)
Balance June 30, 2012 6,464
Direct financing leases
  
Leases Disclosure [Line Items]  
Balance December 31, 2011 256
Reclassifications & Additions / Dispositions (3)
Depreciation/ Amortization Expense or Amortization of Leases (86)
Balance June 30, 2012 167
Assets held for sale or lease
  
Leases Disclosure [Line Items]  
Balance December 31, 2011 153
Reclassifications & Additions / Dispositions 797
Balance June 30, 2012 $ 950