Commitments and Contingencies 2 (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Operating Leases - Future Minimum Rental Payments
Operating Leases - Future Minimum Rental Payments 2012	$ 144,738
Operating Leases - Future Minimum Rental Payments 2013	124,623
Operating Leases - Future Minimum Rental Payments 2014	98,932
Operating Leases - Future Minimum Rental Payments 2015	80,187
Operating Leases - Future Minimum Rental Payments 2016	62,601
Operating Leases - Future Minimum Rental Payments After 2016	695,895
Operating Leases - Future Minimum Rental Payments Total	1,206,976
Operating Leases - Future Minimum Rental Receipts
Operating Leases - Future Minimum Rental Receipts 2012	37,699
Operating Leases - Future Minimum Rental Receipts 2013	31,165
Operating Leases - Future Minimum Rental Receipts 2014	25,286
Operating Leases - Future Minimum Rental Receipts 2015	16,497
Operating Leases - Future Minimum Rental Receipts 2016	6,710
Operating Leases - Future Minimum Rental Receipts After 2016	925
Operating Leases - Future Minimum Rental Receipts Total	118,282
Capital Leases - Future Minimum Rental Payments
Capital Leases - Future Minimum Rental Payments 2012	548
Capital Leases - Future Minimum Rental Payments 2013	564
Capital Leases - Future Minimum Rental Payments 2014	573
Capital Leases - Future Minimum Rental Payments 2015	582
Capital Leases - Future Minimum Rental Payments 2016	594
Capital Leases - Future Minimum Rental Payments After 2016	5,305
Capital Leases - Future Minimum Rental Payments Total	8,166
Less: Interest expense	(3,830)
Present value of minimum lease payments	4,336	4,385
Less: Current portion of obligations under capital leases	127	100
Long-term portion of obligations under capital leases	$ 4,209	$ 4,300

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid within one year (or one operating cycle, if longer) of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45023-112735

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 7, 10, 13

-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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682