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