Investment in Direct Financing Leases - (Details) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Capital Leases, Net Investment in Direct Financing Leases [Abstract]    
Minimum lease payments receivable $ 20,026 $ 21,487
Estimated residual value of leased assets 27,854 27,854
Unearned income (12,398) (13,342)
Total real estate assets under direct financing leases $ 35,482 $ 35,999