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Other $ / shares in Units, $ in Thousands | 12 Months Ended
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Dec. 31, 2016 USD ($) shares | Dec. 31, 2015 USD ($) shares | Dec. 31, 2014 USD ($) $ / shares shares
Additional Common Shares Authorized | shares | 13,000,000 |  |
Stock Repurchase Program, Number of Shares Authorized to be Repurchased | shares | 13,000,000 |  |
Stock Repurchased and Retired During Period, Shares | shares | 0 | 0 | 31,240
Treasury Stock Acquired, Average Cost Per Share | $ / shares |  |  | $ 56.87
OP units repurchased and retired | $ 0 | $ 0 | $ 1,777
Partially Owned Properties Acquired Properties |  |  | 1
Partially Owned Units Acquired Units |  |  | 268
Change in Paid In Capital |  |  | $ 2,300
Reduction In Partially Owned Properties |  |  | 2,200
Reduction In Other Liabilities |  |  | 1,000
Partner Buyout [Member] |  |  |
Purchase Price, Business Acquisition, Cost of Acquired Entity |  |  | $ 5,500
ERPOP [Member] |  |  |
Stock Repurchased and Retired During Period, Shares | shares | 0 | 0 | 31,240
OP units repurchased and retired | $ 0 | $ 0 | $ 1,777
NONCONTROLLING INTERESTS – PARTIALLY OWNED PROPERTIES |  |  |
Land parcels acquired |  |  | 1

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