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Marketable Securities (Details) (USD $) | Jun. 30, 2014 | Dec. 31, 2013
--- | --- | ---
Investment Holdings [Line Items] |  |
Fair Value | $ 35,729,000 | $ 31,522,000
Macerich Interest [Member] |  |
Investment Holdings [Line Items] |  |
Macerich Common Shares | 535,265 | 535,265
Economic basis per share (in dollars per share) | $ 56.05 |
GAAP Cost | 30,000,000 |
Fair Value | $ 35,729,000 | $ 31,522,000
Closing share price (in dollars per share) | $ 66.75 | $ 58.89

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