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Marketable Securities (Details) (Macerich Interest [Member], USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012
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 | 31,522,000 | 31,206,000
Closing share price (in dollars per share) | $ 58.89 | $ 58.30
Unrealized Gains | $ 316,000 | $ 1,206,000

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