Investments In Unconsolidated Joint Ventures (12 Vreeland Associates, L.L.C.) (Narrative) (Details)	12 Months Ended
Dec. 31, 2012 sqft
12 Vreeland Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in venture	50.00%
Area of property (in square feet)	139,750
Holding and distribution pattern under operating agreement	M-C Vreeland holds a 50 percent interest in 12 Vreeland Associates, L.L.C., with S/K Florham Park Associates, L.L.C. (the managing member) and its affiliate holding the other 50 percent.
S/K Florham Park Associates LLC [Member]
Schedule of Equity Method Investments [Line Items]
Third party ownership percentage	50.00%

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant