Real Estate Investments Business Acquisitions (Details) (Unconsolidated Properties [Member], Lake Grove [Member] [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012
Unconsolidated Properties [Member] \| Lake Grove [Member] [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	1/17/2012
Business Acquisition, Name of Acquired Entity	Lake Grove Commons
Business Acquisition Location, City and State	Lake Grove, NY
Equity Method Investment, Ownership Percentage	40.00%
Business Acquisition, Cost of Acquired Entity, Purchase Price	$ 72,500
Noncash or Part Noncash Acquisition, Debt Assumed	31,813
Acquired Finite-lived Intangible Asset, Amount	5,397
Acquired Finite Lived Intangible Liability, Amount	$ 4,342

Month, date and year in which the acquirer obtains control of the acquiree.

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-Glossary Acquisition Date

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+ Details

- Definition

Name of the acquired entity.

+ References+ Details

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References+ Details

- Definition

The amount of debt that an Entity assumes in acquiring a business or in consideration for an asset received in a noncash (or part noncash) acquisition. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References+ Details