Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Other Receivables
Total loan receivables and other financing receivables	$ 421,453	$ 421,357
Payment Activity [Member] \| Performing [Member]
Class of Financing Receivable
Direct financing leases	406,549	409,541
Other Receivables
Long-term receivable included in other assets	973	786
Advances to joint venture included in investment in and advances to joint ventures		830
Other Internal Metrics [Member] \| Performing [Member]
Other Receivables
Advances to joint venture partner (Note 6)	$ 13,931	$ 10,200

The net investment in direct financing leases as of the balance sheet date consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 23

-Subparagraph a(i)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6952072&loc=d3e45377-112738

Name:	us-gaap_CapitalLeasesNetInvestmentInDirectFinancingLeases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant