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Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Jan. 01, 2019 | Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |
Retained earnings | $ 248,443 | $ 302,543 |  |  |
Change in fair value of marketable securities (see Note 5) | $ (11,990) | $ 0 | $ 0 |  |
Closing share price (in dollars per share) | $ 43.28 | $ 65.68 |  |  |
Real estate, net | $ 730,270 | $ 754,324 |  |  |
Cash and cash equivalent maturity maximum | 3 months |  |  |  |
Allowance for doubtful accounts | $ 671 | $ 1,501 |  |  |
Accounting Standards Update 2016-01 |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |
Retained earnings |  |  |  |  | $ 5,156
Macerich |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |
Change in fair value of marketable securities (see Note 5) | $ (11,990) |  |  |  |
Closing share price (in dollars per share) | $ 43.28 | $ 65.68 |  |  |
Subsequent Event | Accounting Standards Update 2016-02 |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |
Finance lease, right-of-use asset |  |  |  | $ 5,400 |
Finance lease, liability |  |  |  | $ 5,400 |
Rego Park I |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |
Percentage of cash mortgage collateralized | 100.00% |  |  |  |

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