Real Estate Investments (Narrative) (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
In-place leases \| 421 W. 54th Street
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 0.3

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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