Leases and Restricted Cash (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Net Investments in Direct Financing Leases
Total minimum lease payments to be received	$ 622,912	$ 701,442
Estimated unguaranteed residual value of leased properties	194,965	194,965
Initial direct costs	554	587
Less unearned revenue	(448,890)	(481,299)
Total	409,541	415,695
Less current portion	6,074	5,635
Total	$ 403,467	$ 410,060

The net amount due within one year of the balance sheet date or the normal operating cycle, if longer, 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

+ Details

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

- Definition

The net amount due after one year of the balance sheet date or beyond the normal operating cycle, if longer, 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.

+ References

+ Details

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

- Definition

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.

+ References

+ Details

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

- Details

Name:	us-gaap_CapitalLeasesNetInvestmentInDirectFinancingLeasesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The remaining (unamortized) difference between the gross investment in a direct financing lease and the cost or carrying amount, if different, of the leased property as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 18

-Subparagraph b

-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 Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 23

-Subparagraph a(i)(d)

-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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(4)

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

+ Details

Name:	us-gaap_CapitalLeasesNetInvestmentInDirectFinancingLeasesDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Remaining unamortized costs as of the balance sheet date that were essential to acquiring the lease, and that would not otherwise have been incurred without the lease agreement, including evaluating the lessee's credit condition, guarantees, and collateral and costs incurred negotiating, processing, and closing the lease agreement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(3)

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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 23

-Subparagraph a(i)(c)

-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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 5

-Subparagraph m

-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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 25

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=6748888&loc=d3e40246-112709

+ Details

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

- Definition

Amount of remaining payments as of the balance sheet date that lessees are obligated to make or can be required to make under direct financing leases, including any guarantee of residual value and executory costs. The amount also includes any guaranteed rental payments by an unrelated third-party provided that are financially capable of making such payments.

+ References

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)(a)

-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)(1)

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

+ Details

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

- Definition

The estimate of the lease property's economic value at the end of the direct financing lease term excluding any amounts guaranteed by either the lessee or a third-party.

+ References

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)(b)

-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)(2)

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

+ Details

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