| Tenant Leases (Details) (USD $) In Thousands, unless otherwise specified | 9 Months Ended | 
|---|---|
| Sep. 30, 2013 | |
| Property Subject to or Available for Operating Lease [Line Items] | |
| October 1 through December 31, 2013 | $ 125,682 | 
| 2014 | 495,819 | 
| 2015 | 444,042 | 
| 2016 | 399,155 | 
| 2017 | 348,011 | 
| 2018 and thereafter | 1,290,172 | 
| Total | $ 3,102,881 | 
| Tenant Leases [Member] | |
| Property Subject to or Available for Operating Lease [Line Items] | |
| Operating leases with various expiration dates through year | Mar. 31, 2033 | 
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- Definition Date which lease or group of leases is set to expire, in CCYY-MM-DD format. No definition available. 
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- Definition Future minimum rental payments in aggregate as of the balance sheet date under operating leases. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future rental payments receivable within one year of the balance sheet date under an operating lease. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future rental payments receivable within the fifth year from the balance sheet date under an operating lease. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future rental payments receivable within the fourth year from the balance sheet date under an operating lease. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future rental payments receivable within the third year from the balance sheet date under an operating lease. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future rental payments receivable within the second year from the balance sheet date under an operating lease. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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