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Marketable Securities (Details) (Macerich Interest [Member], USD $) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 | Sep. 30, 2013
Macerich Interest [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Macerich common shares | 535,265 | 535,265
Economic basis per share | $ 56.05 | $ 56.05
GAAP Cost | $ 30,000,000 | $ 30,000,000
Fair Value | 30,210,000 | 30,210,000
Closing share price (in dollars per share) | $ 56.44 | $ 56.44
Unrealized net loss | $ (2,425,000) | $ (996,000)

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