Investment in Leases (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Leases Disclosure [Line Items]
Balance December 31, 2011	$ 8,276
Reclassifications & Additions / Dispositions	(59)
Depreciation/ Amortization Expense or Amortization of Leases	(970)
Balance September 30, 2012	7,247
Operating leases
Leases Disclosure [Line Items]
Balance December 31, 2011	7,867
Reclassifications & Additions / Dispositions	(602)
Depreciation/ Amortization Expense or Amortization of Leases	(827)
Balance September 30, 2012	6,438
Direct financing leases
Leases Disclosure [Line Items]
Balance December 31, 2011	256
Reclassifications & Additions / Dispositions	(3)
Depreciation/ Amortization Expense or Amortization of Leases	(123)
Balance September 30, 2012	130
Assets held for sale or lease
Leases Disclosure [Line Items]
Balance December 31, 2011	153
Reclassifications & Additions / Dispositions	546
Depreciation/ Amortization Expense or Amortization of Leases	(20)
Balance September 30, 2012	$ 679